JPS5839490A - Method of marking non-carrier polymer film and asymmetric non-carrier polymer film - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for marking carrier-free polymer membranes for filtration, particularly microbial filtration, ultrafine filtration, and reverse osmosis.

Kokote "What is carrier-free J ("trMg@rlos?

This means that the membrane is not more or less firmly connected to the support structure carrier, for example a filter cart y, but that the planar periphery is neither reinforced nor supported.

This is extremely problematic since such carrier-free polymer films are often only a few micrometers thick and have very sensitive structures. Although marking is absolutely necessary, it has hitherto been impossible to mark without damaging the extremely sensitive carrier-free polymer membrane 62.

For example, for membranes used for filtration, Special C: microbial filtration and ultrafine particle filtration, the pore size and the material from which the membrane is made, that is, the type of membrane, must be specified.

Asymmetric (two made; special (membrane ζ used for double osmosis)
Second, its activity is 11! i must be clearly determined. The reason is that in such asymmetric membranes, knowing the active layer is crucial for performing reverse osmosis. If the active layer of the non-contrast polymeric membrane is not properly recognized and the required active layer of the membrane is not used, the membrane will fail under pressure. However, even a skilled person may be able to determine the active layer of an asymmetric polymer membrane or the pore size of a filtration membrane.
To identify asymmetric polymer membranes, which cannot be confirmed without auxiliary means and testing, dye adhesion tests or drying tests on membrane samples are used, both of which render the membrane unusable within the area being tested. . When a sample is removed from a membrane body to be used for testing, there is a risk of misunderstanding the active layer between the sample and the body.

Therefore, it is actually desired to attach symbols directly to the membrane itself. Since this type of membrane is mechanically extremely sensitive, chemically only highly selectively bistable, and for that purpose must contain absolutely no other substances, carrier-free polymer membranes have traditionally been used. It was prohibited to attach symbols directly. Attempts to directly mark the polymer film fail in that most polymer films are mechanically damaged; the solvents contained in conventional ψ printing inks often dissolve the film material itself. Furthermore, many membranes, especially asymmetric membranes for reverse osmosis, must be kept constantly moistened with water to avoid damaging the membrane structure, but these membranes are often printed with waterproof symbols. Adds difficulty.

Moreover, since the active layer of asymmetric polymeric membranes is generally only about α1μ thick at most, there is a great risk of mechanical damage when printing on the membrane. Therefore, printing of the membrane is done at best in peripheral areas not needed for filtration or reverse osmosis. However, if this peripheral region is separated before the membrane is used, confusion of the five sides of the membrane or of the entire layer may again occur.

The problem underlying the invention is to provide a method by which the surface area of a membrane used for filtration or reverse osmosis can be marked without any influence on the filtration or reverse osmosis properties of the membrane. .

In order to solve this problem, the present invention has completed a method having the features listed in claim 1.

In addition, the present invention provides an asymmetric carrier-free polymeric membrane with distinct markings on the active layer.

The essence of the invention is that in order to mark an unsecured polymeric membrane, rather than printing the symbol on the membrane itself, the symbol is first printed on the substrate and poured or coated with the injection material in advance. The process is to create a film. This injection material is generally a membrane poly! -〇It is an organic solvent solution. This O solution may contain fillers. Depending on the solvent contained in the injection material
First, the print on the substrate is pushed out from the substrate and is received by the membrane material. When the membrane hardens by settling or drying, the printing ink migrates towards the membrane along the contours printed on the substrate and away from the substrate. The membrane is absolutely not damaged by this method, it is chemically stable and the membrane symbol remains unaffected and clear.

According to the invention, the injectable material is poured to form a film, and the substrate to be printed before injecting is preferably an endless belt of metal, rubber or plastic with a smooth surface. A plain belt made of special steel with a textured surface is suitable.

Do not affect the film formation process, when pouring the injection material onto the substrate, the printing ink corresponding to the symbol printed on the substrate must be at least scratch-resistant and especially completely dry. .

When the injection solution was poured onto the printed substrate, it was shown that the printing ink printed on the substrate migrated into the film.

Therefore, the cleanest and best results are obtained with a solvent or solvent-based (hereinafter also referred to as solvent-based) k soluble printing ink that acts as the solvent phase in the injection material. Further, when performing the marking method according to the present invention, it is preferable to use a printing ink that is waterproof at least after being transferred onto the substrate or into the film. Printing inks that meet these conditions should be confirmed by the ink manufacturer's instructions or, if in doubt, by a direct dissolution test. Further, since there are countless compositions of printing materials on the market that meet these requirements, a detailed description thereof will be omitted here. When making such an asymmetric membrane by injection, a porous inert sponge layer is formed on the base side and one active layer is formed on the air side of the injection layer. It is particularly advantageously used. The printing ink is received in the permeable, filtration-inert sponge layer when marking the asymmetric membrane. When marking a symbol on a transparent film, it is advantageous for 4IK to print the symbol neatly on the base. And the underside of the inactive layer or permeation-inert asymmetric membrane is printed inside out, so that the symbol shows right through the active layer. In the case of opaque asymmetric membranes, which help clearly identify the active layer of the membrane, the printing on the substrate is often done inside out, and the inert underside of the asymmetric membrane is printed integrally. On the other hand, in the case of transparent or see-through membranes, the user's knowledge of II, when read literally, indicates that the active layer is on top, and in the case of opaque membranes, the user will be able to see the unprinted markings on the membrane. is the active layer. The underside of the printed inert can be read as required with the required marking symbols.

Even when a relatively thick layer of printing ink is placed on the base and it dries completely, there is no trace of paint left behind! [K
Therefore, it was found that it was removed.

The method of the invention can be used in conventional continuous production, in which an endless belt is used as the substrate.

The solidified or pre-solidified membrane was removed. After that, it is best to immediately make a new print on the base. The printed ink is then dried, at least so that it cannot be rubbed off, by the time the new injection material reaches its location on the printed substrate. With this 5Kt, the start of manufacture and date of manufacture, which are especially important for the manufacturer's warranty, are printed without any problems.

According to the method of the invention, membrane symbols can be printed in a single color or in multiple colors. This means that the membrane data, e.g. membrane material,
This shows the possibility of color-coded codes such as pore size or purpose on the membrane.

Especially when using printing inks of different colors.

Adjust the solvent system used for the respective printing ink, i.e. the individual solvents of the mixed solvent, and adjust these solvent O selections so that all the ink printed on the substrate is completely dry and the injector AK It can be guaranteed that it will not be tampered with.

5. Today, poly! is most commonly used for filtration and reverse osmosis. - The film is probably an acetyl cellulose film based on its quantity. To print this acetyl cellulose film by the method of the present invention, for example, use conventional vidament or dyes, especially soot, etc. for ink colors, etc. The color can be printed using tutaric acid-based dyes and printing inks. As binder for such printing inks, the usual Pine Xs based on polyamides, polyacrylate esters or nitrocellulose are used. Preferred solvents for printing inks of this type are mixed ketones, such as cl-0
Adjustment of the solvent system with the 4-ketone compound is done depending on the drying time required. Ester or Schiff's hexane can also be used as a solvent instead of the 4-ketone compound. The production of such printing inks is easy for those skilled in the art. The numerous commercially available printing inks can, of course, not only be employed in the process of the invention, but also be adapted to the desired special conditions relatively easily by changing the solvent phase.

Claims (1)

[Claims] 1. A base surface on which symbols are printed with printing ink (= injection material for film formation is poured, and after the formed film hardens together with the printing ink, it is removed from the base by a method known per se) A method for marking a carrier-free polymer membrane for filtration and reverse osmosis, characterized in that: λ is an endless belt with a smooth surface made of metal, rubber or plastic material 1. 5. The method according to claim 1, characterized in that the base is a polished copper strip. The method according to any one of claims 1 to 3, characterized in that the printing ink on the substrate is dried to prevent it from being rubbed off. & A method according to any one of claims 1 to 4, characterized in that the dried printing ink is soluble in the solvent or solvent system of the film-forming injection material.6 , The method according to any one of claims 1 to 5, characterized in that the printing ink is water resistant after being transferred to the sliding door. 8. The method according to any one of claims 1 to 6, characterized in that the opaque membrane is printed upside down. 8. On the back side of the membrane that does not perform filtration and permeation 9. An asymmetrical polymer membrane for filtration and reverse osmosis, characterized in that it is marked with symbols and/or markings in printing ink.9. 9. The membrane according to claim 8, characterized in that a printing ink is used which is soluble in a solvent of #1L or a #1L solvent system. 12. The membrane according to claim 8 or 9, characterized in that the membrane is provided with: 12.