JPH0521995B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to surface treatment of fiber fabric by electrodeposition coating method, and more specifically, it is suitable for forming a uniform coating surface on mesh-like woven and knitted fabrics such as filter cloth and screen cloth. This relates to processing methods.

Conventional methods for applying a treatment agent when surface-treating a fiber fabric include immersion in a solution, emulsion or suspension of the treatment agent, squeezing with a mangle after immersion, spraying, Coating methods and the like have been used.

A similar method is applied to mesh-like woven and knitted fabrics, but in this case, the treatment agent is used to prevent the gaps between the warp and weft from being filled with the treatment agent (hereinafter referred to as clogging). After application, special measures are taken, such as blowing off the processing agent in the gap between the warp and weft with an air stream or suctioning it under reduced pressure.

However, in such a method, the state of adhesion of the treatment agent becomes non-uniform, resulting in variations in the thickness of the treatment agent film, variations in the shape of the openings, variations in the aperture ratio, and even macroscopic differences between the front and back surfaces may occur.

Therefore, this method is extremely unsatisfactory as a processing method for filter cloths, printing screens, and optical screens that require uniformity in aperture shape and aperture ratio.

The present inventors have arrived at the present invention as a result of repeated research into a processing method that can apply such a highly uniform treatment agent and obtain a uniform opening shape and opening ratio.

That is, the present invention focuses on metallization technology that can impart necessary and sufficient conductivity to the surface of non-conductive fibers, and electrodeposition coating technology that can form a uniform treatment agent film on the surface of conductive substances. This made possible a new processing method that had not been seen before.

The gist of this method is to form a metal film on the surface of fibers of fiber fabric, which is inherently non-conductive, by dry or wet plating, and then apply a treatment agent uniformly to the surface of the metal film using an electrodeposition coating method, and to intertwine The treatment agent is applied so as to cover the dots.

Next, an example of processing a mesh fabric according to the present invention will be explained based on FIGS. 1 to 3.

This mesh fabric has a continuous metal film 4 coated around the filament yarns 1 and 2 of synthetic fibers and around the intertwining points 3 of warp and warp yarns by electroless plating method, and then the surface of the metal film is coated by electrodeposition coating. This is an example in which the surface coated with this synthetic resin is further coated with a continuous metal film 6 by a dry plating method, if necessary.

The method of the present invention can be applied to all commonly available woven and knitted fabrics, but the characteristics of the method of the present invention are particularly useful for mesh woven and knitted fabrics that are particularly susceptible to treatment agent adhesion. Filter base materials and screen base materials that require uniformity in fiber diameter, aperture shape, and aperture ratio are suitable.
As the fibers used, organic synthetic fibers such as polyester and polyamide are preferably used. When using these fabrics, impurities such as dirt, oil, and sizing agents adhering to the fibers must be removed in advance by desizing, scouring, degreasing, etc., as they will have a negative effect on the plating process that will be performed later. There is.

Next, as a method for metallizing the fiber surface, a combination of known chemical metal plating, that is, so-called electroless plating, which goes through sensitization treatment with a reducing agent and pretreatment with activation treatment with a noble metal ion-containing solution, and electroplating are used. The method is basically applicable.
The metals deposited and adhered by this electroless plating include nickel, copper, cobalt, chromium, zinc,
Examples include tin and iron, but in the method of the present invention, copper or nickel is preferred from the viewpoint of ease of plating and economic efficiency. Of course, the metal ratio must be adjusted so that the electrodeposition coating progresses uniformly and without unevenness, but the surface resistance value must be 1 Ω/hole or less, preferably 0.1 Ω/hole or less, and conductive performance is required.
Dry plating methods such as vacuum deposition, sputtering, and ion plating can also be applied as metallization methods, but depending on the material, the metallization may be from 1Ω/hole to 0.1Ω/hole.
A method using wet plating is preferable since conductivity of less than Ω/hole cannot be obtained. A dry plating method can also be used to form the metal film 6.

In particular, the surface structure of the metal film is such that the film thickness x is 0.01≦
x≦6μm and has irregular unevenness on its surface, the distance y between the lowest point and the highest point of the unevenness is 0.05≦y≦5μm, and the density z of the unevenness is 100 (μm).
m) If 25≦z≦500 metallized fibers are used per ² , the effect of applying the finishing agent by the following electrodeposition coating method is significantly improved. Metallized fibers having the above characteristics can be produced by, for example, treating a polyester filament with an aqueous solution of caustic soda to reduce the weight by 5 to 40%, then subjecting it to low-temperature plasma treatment, and then electroless plating to form a metal film with a desired thickness. You can get it by twisting it. Of course, it is possible to obtain metallized fibers having the above characteristics by other methods by selecting and combining various conditions.

Next, an electrodeposition coating method is used to apply various finishing agents to the metal-plated fiber surface of the present invention. This electrodeposition coating is impossible on the surface of synthetic fibers, which are not inherently conductive, and is only possible by metallizing the surface of the fibers and making them conductive, as in the present invention.

In addition, this electrodeposition coating is a well-known technique that applies the principle of electrophoresis, but since the coating material is adsorbed onto the object to be treated by electrical attraction from within the treatment solution and gradually deposited and layered, A major feature of this method is that it produces a uniform thin film that cannot be obtained using other methods. Using this electrodeposition coating method, a uniform treatment agent film is formed that not only covers the surface of each fiber, but also the intertwining points of the warp and weft, resulting in a uniform opening shape and even opening by external force. The significance of the present invention lies in the production of a durable filter material or screen material that does not easily lose its shape. However, there have been no examples of applying the electrodeposition coating method to fabrics based on non-conductive fibers at a mass production level.

Accordingly, in the present invention, the manufacturing method, particularly the equipment and jig, have been devised in order to achieve mass production of fabrics by electrodeposition coating.

Industrially, continuous processing of long lengths of fabric is desirable, but unlike continuous electrolytic plating, if the adhered paint comes into contact with an electrode roll etc. before it is completely dry, the fabric will immediately become clogged and defective, so batch processing is required. The manufacturing method was devised.

In other words, the key point in this case is to improve the quality of the electrodes in order to obtain a uniform coating film over the entire large fiber surface area, and to improve productivity, how to increase the production amount per batch. There is a crab. These two are simply inversely correlated,
If the treated area per batch is increased unnecessarily, uniform coating becomes impossible.

However, as a result of devising the electrode section and examining the method of attaching the fabric to be treated, we came to devised a jig as shown in FIGS. 1 and 2.

The jig is a pipe made of metal such as stainless steel, and should be called an electrode frame. This electrode frame has both the function of an electrode and the function of a mounting tool for the cloth to be treated, and includes the following components. Namely, the handle for operating the electrode frame and the cable connection part from the DC power source (a), the extension part (b) that allows the fabric to be stretched without sagging in the length direction after the cloth to be treated (e) is attached, and the cloth to be treated (b) is attached. It consists of an extension part C which can stretch the fabric without sagging in the back width direction.

Fig. 4 1 shows the case where the frame length in the width direction and the frame length in the length direction are 1:1.5 or less, and the extension part in the width direction is
is not necessary. Also, A and B are used as handles for both purposes. FIG. 4 2 shows a case where the frame length in the width direction and the frame length in the length direction are 1:1.5 or more, and an extension part in the width direction is also required.

By attaching the cloth to be treated in a double-wound manner around this electrode frame, the length to be treated in one batch is twice the length of the frame, thereby improving productivity. Therefore, for example, it is possible to electrodeposit a fabric of 140 cm x 400 cm per batch, and it is possible to ensure industrially satisfactory productivity and economy. The treatment tank for electrodeposition coating and other parts may have the optimum specifications according to the electrode frame, and the electrode frame may be handled according to known methods.

Once the fabric to be treated is attached to the electrode frame, it is subjected to pre-treatment for electrodeposition coating (degreasing, washing), treatment for electrodeposition coating, post-treatment for electrodeposition coating (washing with water, showering and washing),
Productivity and yield can be ensured by performing a series of treatments such as drying and baking without removing the product from the frame.

In order to form a treatment agent coating film of uniform thickness on metallized fibers, it is necessary to sufficiently control electrodeposition treatment conditions such as treatment solution temperature, voltage, current, and current application time.

Preferably, the electrodeposition treatment conditions are a treatment temperature of 15 to 30°C, a voltage of 40 to 150V, and a current application time of 10 to 60 seconds.

As the treatment agent for electrodeposition coating, various treatment agents in the form of organic or inorganic ion-dispersed particles can be applied. Among the processing agents, particularly as the resin agent, anionic synthetic resins containing melamine resins and acrylic resins as main components are preferred from the viewpoint of preventing clogging.

The synthetic fiber filter material or screen material obtained by the method of the present invention has the following functions:
It has a form and appearance.

That is, (1) the processing agent is uniformly attached, and the aperture shape and aperture ratio are uniform. (2) The intertwining points of the warp and warp yarns are wrapped and fixed by the treatment agent. (3) The surface can be colored arbitrarily. (4) Enclosed with a metal layer, it has electromagnetic wave shielding and static electricity shielding power. (5) When a metal film is further formed on the surface, although the base material is a fiber, the surface physical properties exhibit the properties of a metal. (6) Depending on the type of treatment agent for electrodeposition coating, it has ionic properties such as anions and cations, water repellency, hydrophilic properties,
Functions such as lipophilicity can be imparted to the thread surface. etc.

By combining one or several of these features, it is possible to create a product that meets the intended use. For example, the shield screen attached to the VDT surface to protect the operator's eyes is described in (4) above.
This utilizes the electromagnetic wave shielding ability and static electricity shielding ability of . Note that this screen is colored black, taking advantage of the feature (3). Furthermore, in addition to fixing the intertwining points of the weft and weft threads in (2), it is also possible to create a screen in which the metal layer is closer to a stainless steel screen in which the intertwining points are more stable than the conventional polyester gauze screen by the method of claim 3. . It is also possible to make special filters by taking advantage of the feature (6).

Next, the present invention will be explained in detail based on examples. Note that the present invention is not limited to these examples.

Example 1 A 150 mesh polyester monofilament shear fabric was thoroughly degreased and washed with water, and then treated with caustic soda.
Etching is performed using a 20% by weight aqueous solution so that the weight of the fabric is reduced by approximately 15%. Next, it was subjected to sensitization and activation treatment in the same manner as the electroless plating treatment of general plastic materials, and then wet electroless copper plating treatment was performed with a metal coating amount of 40% by weight and a metal coating thickness of 2 μm. Next, the fabric that has been subjected to this copper plating treatment is
It was wound around the electrode frame shown in the figure, and the sewing machine hanging frame was stretched and attached to the fabric so that there was no slack. After thorough degreasing and washing with water, a DC voltage of 55 V was applied for 40 seconds to electrodeposit a film thickness of 5 μm in a 10% anionic electrodeposition paint.

Next, while attached to the electrode frame, the coating film was dried at 80°C for 20 minutes and then heat treated at 150°C for 30 minutes to completely crosslink and cure the coating, and then removed from the electrode frame. The obtained screen had uniform openings in which the fiber surfaces and intertwining points were covered with a resin film. (See photo A).

Example 2 The screen obtained in Example 1 above was thoroughly degreased and washed with water, and then subjected to pretreatment such as conditioning, sensitization, and activation treatment, and the amount of metal deposited by weight was 20. %, and a wet electroless nickel plating process with a metal film thickness of 3 μm was performed to obtain a screen with surface characteristics as a metal and uniform openings.

Example 3 A polyester shear fabric that had been subjected to wet electroless copper plating in the same manner as in Example 1 above was thoroughly degreased and washed with water, and then treated in a 10% anionic black electrodeposition paint under the same conditions. Electrodeposition, drying, and heat treatment were performed to obtain a screen with a black surface and uniform openings.

Comparative Example The same polyester shear fabric as in Example 1 was colored black by a conventional lacquer coating method.

The condition of the obtained paint film was that it had an uneven surface with cracked parts.
(See photo B).

[Brief explanation of drawings]

Fig. 1 is a front view of the synthetic fiber base fabric used in the present invention, Fig. 2 is a partial sectional view of a screen obtained by processing the synthetic fiber base fabric according to the present invention, and Fig. 3 is a front view of the synthetic fiber base fabric used in the present invention. FIG. 4 is an enlarged cross-sectional view of one fiber taken out, and a front view of an electrode frame for holding a fabric to be treated used in the treatment of the present invention. Figures 5 and 6 are photographs showing the shape of the fibers, of which Figure 5 is an electron micrograph showing that the fiber surface and intertwining points are covered with a resin film, and Figure 6 is a photograph showing the shape of the fibers. This is an electron micrograph showing a hangnail state of the resin film. 1... Warp filament yarn, 2... Weft filament yarn, 3... Intertwining point of warp and weft, 4...
Metal layer, 5...Synthetic resin layer, 6...Metal layer, i...
... Cable connection part, B... Extended part in the length direction, C... Extended part in the width direction, D... Fabric to be treated.

Claims (1)

[Scope of Claims] 1. When applying a finishing agent to a fabric made of organic fibers, a metal film is formed on the surface of the fibers constituting the fiber fabric, and then the finishing agent is applied by electrodeposition using the conductivity of the metal. A method for processing a fiber fabric, which comprises adhering it onto the metal film by a coating method. 2. The method for processing a fiber fabric according to claim 1, wherein the fiber fabric is a mesh-like woven or knitted fabric. 3. The method for processing a fiber fabric according to claim 1 or 2, wherein the formation of a metal film on the fiber surface is carried out by chemical plating. 4. The method for processing a fiber fabric according to any one of claims 1 to 3, wherein the organic fiber is an organic synthetic fiber. 5. The method for processing a fiber fabric according to any one of claims 1 to 4, wherein the organic fiber is a polyester filament. 6 Film thickness x satisfies 0.01≦x≦6μm, and
It has irregular unevenness on its surface, the distance y between the lowest point and the highest point of the unevenness is 0.05≦y≦5μm, and the density z of the unevenness is 25≦z≦500 pieces per 100 (μm) ² . A method for processing a fiber fabric according to any one of claims 1 to 5, wherein a metal film is formed in a certain manner.