BE1021624B1 - DEVICE AND METHOD TO APPLY SURFACE COATINGS - Google Patents

Abstract

Apparatus and method for applying surface coatings The present invention provides a method for depositing a polymeric coating onto, e.g. a piece of cloth, and further provides a plasma chamber for depositing polymeric coating on a piece of cloth, e.g. a textile material, the plasma chamber consisting of a plurality of electrode layers arranged successively within the plasma chamber, at least two adjacent electrode layers being radio frequency electrode layers or ground electrode layers, providing both sides of a piece of fabric with a surface coating.

Description

Device and method for applying surface coatings

The present invention encompasses devices and methods for applying surface coatings and is particularly, but not exclusively, related to devices and methods for depositing protective polymer coatings on fabrics and the resulting coating fabrics.

The words fabric or fabrics as used in this application include both non-woven and woven or knitted materials, which can be assembled into articles such as pieces of clothing for daily use, for use in industrial environments, as personal protective clothing, for sports and leisure time and so on. Other articles in which fabrics can be transformed are merchandise such as backpacks, umbrellas, tents, screens, curtains, sofas, carpets, household textiles, sleeping bags, etc. Fabrics are also used as filtration media for use in eg. heat, ventilation or air conditioning systems (HVAC systems) or for use in exhaust filters, diesel filters, liquid filters, filtration media for medical applications, etc. Often in HVAC applications the fabrics are not woven, knitted or otherwise formed in materials with a regular organization of the fibers. The methods and processes of this invention can be applied to all of these substances.

It is known for coatings, e.g. polymeric coatings, deposited on fabrics for the purpose of protecting fabrics from wear such as the wear that occurs during daily use or repeated washing.

It is also known to deposit coatings on pieces of fabric by means of role-to-role systems. Roll-to-roll systems as known in the domain typically consist of electrode arrangements such as those shown in Figures 2 and 3. With such arrangements, monomer is polymerized on a single side of a piece of fabric. In order to provide both sides of the piece of fabric with a polymeric coating it is necessary, after depositing a coating on one side, to remove the roll from the machine, turn it through 180 °, and treat it again in the machine on the other side is provided with a polymeric coating. It is clear that this known method requires a considerable amount of time to deposit a coating on both sides. Furthermore, a considerable time is lost due to the need to take the roll out of the machine, rotate it through 180 ° and place it back in the machine.

Documents that are part of the professional knowledge also describe the use of a carrier gas, e.g. an inert gas such as argon, nitrogen or helium to generate the plasma. Furthermore, documents describing the prior art state that more carrier gas is used than monomer, resulting in a ratio of carrier gas flow to the monomer flow of, for example. 100: 1 to 2: 1.

It is a non-exclusive aspect of the present invention to provide an apparatus and method for increasing the quality of the coatings and reducing the time required to deposit them.

In a first aspect, the invention provides a plasma chamber for depositing a polymeric coating on a piece of fabric, e.g. a textile material, wherein the plasma chamber comprises a plurality of electrode layers that are successively suitable within the plasma chamber, wherein at least two adjacent electrode layers are radiofrequency electrode layers or wherein at least two adjacent electrode layers are grounded electrode layers (ground electrode layers).

In another aspect of the present invention, a plasma chamber is provided for depositing a polymeric coating on a piece of fabric, such as a textile material, the plasma chamber comprising a plurality of electrode layers, each having a generally flat (planar) or plate-shaped shape, successively suitable within the plasma chamber, wherein at least two adjacent electrode layers are radiofrequency electrode layers or grounded electrode layers.

Preferably, the at least two adjacent electrode layers are radiofrequency electrode layers.

Preferably, the outer pair of electrode layers consists of grounded electrode layers.

In another aspect of the present invention, a plasma chamber is provided with at least two pairs of electrode layers, the outer pair of electrode layers being either grounded electrode layers or radiofrequency electrode layers.

Preferably, the plasma chamber comprises a pair of radiofrequency electrode layers and a pair of grounded electrode layers, e.g. positioned according to M / RF / RF / M or RF / M / M / RF, where "M" indicates a grounded electrode layer, "RF" a radiofrequency electrode layer, and where "/" indicates the positions where the substance between the electrode layers passes.

Preferably, the plasma chamber has further pairs of radiofrequency or grounded electrode layers, e.g. according to the arrangement RF / M / RF / RF / M / RF or M / RF / M / M / RF / M or M / RF / M / RF / RF / M / RF / M or RF / M / RF / M / M / RF / M / RF or RF / M / RF / M / RF / RF / M / RF / M / RF or M / RF / M / RF / M / M / RF / M / RF / M or M / RF / M / RF / M / RF / RF / M / RF / M / RF / M or RF / M / RF / M / RF / M / M / RF / M / RF / M / RF and so on.

In an alternative embodiment, the plasma chamber comprises a first electrode set and a second set of electrodes, the first and second electrode set arranged on either side of a passage for receiving a substance.

Preferably, one or both of the first and second set of electrodes comprise an inner electrode layer and a pair of outer electrode layers.

Preferably, the inner electrode layer is a radio frequency electrode layer and the outer electrode layers are grounded electrode layers, e.g. according to the settlement M * RF * M / M * RF * M or M * RF * M / M * RF * M / M * RF * M and so on.

Conversely, the inner electrode layer may be a grounded electrode layer and the outer electrode layers are radiofrequency electrode layers, e.g. according to the arrangement RF * M * RF / RF * M * RF or RF * M * RF / RF * M * RF / RF * M * RF and so on.

Preferably, the plasma chamber may comprise further electrode sets, for example a third, fourth, fifth and sixth electrode set and so on. For example when a third electrode set is added, e.g. M * RF * M / M * RF * M / M * RF * M, then a cover layer is deposited on both sides of the fabric in two passages.

In all embodiments of the invention wherein the electrode layer is a radio frequency electrode layer, the electrode layer may also include a heat controller, e.g. a hollow portion such as a tube to receive a heat regulator fluid.

When the electrode layer is of the grounded type, the electrode layer need not include a heat controller. The electrode layers of this type can thus simply be a flat plate, grid or other configuration suitable for generating a plasma when positioned next to a radiofrequency electrode layer.

The electrode layers are preferably flat or plate-shaped. An advantage of such a configuration is that the generated plasma is evenly distributed over the surface of the electrode set. Consequently, the rate at which monomer is polymerized on the substrate is the same at any location on the substrate, leading to improved uniformity.

Preferably, the heat controller includes tubes that form a path that bends around itself at about 180 ° at regular intervals to form an electrode that is substantially flat.

Preferably, the heat controller has a diameter of about 2.5 to 100 mm, more preferably of about 5 to 50 mm, even more preferably of about 5 to 30 mm, such as 25, 20 or 15 mm, for example 10 mm.

The heat controller preferably has a wall thickness of about 0.1 to 10 mm, more preferably of about 0.25 mm to 5 mm, even more preferably of about 0.25 to 2.5 mm, e.g. 1.5 mm.

The distance between the heat controller before and after the bend of about 180 ° is between 1 and 10 times the diameter of the heat controller, such as about 3 to 8 times, e.g. 5 times the diameter of the heat regulator.

The heat controller preferably consists of a conductive material such as a metal, e.g. aluminum, stainless steel or copper. Other conductive materials can be considered.

Preferably, the or each radiofrequency electrode layer generates a high frequency electric field at a frequency of 20 kHz to 2.45 GHz, more preferably from 40 kHz to 13.56 MHz, with 13.56 MHz being preferred.

Preferably, the plasma chamber further comprises localization and / or attachment means such as one or more connector plates and / or the chamber walls to attach each electrode layer or electrode set to the desired position within the plasma chamber.

Preferably, the localization and / or attachment means can be removed from the plasma chamber, e.g. by sliding it out of the plasma chamber.

The plasma chamber preferably has one or more inlets to introduce a monomer into the plasma chamber.

Preferably, each inlet monomer feeds to a monomer distribution system that distributes the monomer evenly throughout the chamber. For example, the monomer inlet can feed monomer to a manifold that feeds the chamber.

Preferably, the vaporized monomer is capable of initiating the plasma, thereby avoiding the use of an inert gas such as helium, nitrogen or argon as carrier gas.

However, the Applicant has discovered that in some situations the addition of a small amount of carrier gas leads to a better stability of the plasma within the plasma chamber, whereby a more uniform thickness of the deposition layer is obtained. The ratio of carrier gas to monomer is preferably equal to or lower than 1: 4.

Preferably, the carrier gas is an inert gas such as helium or argon.

Preferably, the carrier gas and the monomer are mixed before flowing into the chamber, which contributes to the quality and uniformity of the carrier gas and monomer mixture before processing.

The device also has a monomer vapor supply system. Monomer is evaporated in a controlled manner. Measured amounts of monomer vapor are supplied into the plasma chamber through a preferably temperature controlled supply line.

Preferably, the monomer is evaporated at a temperature of 50 to 180 ° C, more preferably, 100 to 150 ° C, the optimum temperature depending on the physical properties of the monomer. The temperature of at least a part of the monomer vapor supply system can be controlled according to a sloping (rising or falling) temperature profile. The temperature profile will typically be slightly rising from the location where the monomer is evaporated, and this to the end of the supply line. In the vacuum chamber, the evaporated monomer will expand and the required temperatures at which no condensation will occur in the chamber and further to the pump will typically be lower than the temperatures of the supply line.

In situations where small amounts of carrier gas are used, the carrier gas can be supplied from a gas bottle, tank or reservoir. The flow is controlled by a mass flow controller. After having passed the mass flow regulator, the carrier gas ends up in the monomer supply line, the monomer having already separately passed a flow regulator in order to guarantee a stable gas flow and monomer flow in this way.

A minimum distance of a few mm is preferably provided between the electrodes and the surface of the material on which a cover layer must be deposited. More preferably, this distance is from 10 to 100 mm, e.g. 10 to 90 mm, take less than 80, 70, 60 or 50 mm, preferably 15 to 50 mm.

The plasma chamber preferably contains a plurality of rollers to guide a piece of fabric between each electrode layer or each electrode set.

The rollers are preferably heated to avoid the presence of cold points where the monomer could condense. The rollers are preferably heated from room temperature from about 20 ° C to 85 ° C, more preferably from 25 to 70 ° C, for example 30 to 60 ° C. The rollers are preferably heated with water, oil or other liquids or combinations thereof, most preferably with water. The rollers are preferably provided with a temperature control system that serves to regulate the temperature in order to avoid significant temperature differences.

The rollers can preferably be divided into two categories: pull force sensors and normal rollers. For stiff textile materials, such as thick films or foils, the rollers do not have to be driven individually. It is sufficient that the take-up roller is driven at a certain speed, and all other rollers will start rolling through this take-up movement.

For more fragile materials, such as textiles for filtration and clothing, most or all rollers are driven individually to prevent damage to or tearing of the fabric or material due to extreme stresses. For the most fragile materials, e.g. membranes or thin non-woven fabrics with an open structure, all rollers are driven individually and can be adjusted individually or as a group, e.g. to optimize the processes of fragile textile materials.

The plasma chamber preferably comprises one or more tensile force sensors which can be calibrated as soon as a predetermined basic pressure is reached and before the first process step or unwinding or winding up of the substance is started, e.g. for outgassing, or before the gas inlet is opened and the electromagnetic field is turned on for pre-treatment, or before the gas inlet is opened and the electromagnetic field is turned on before the deposition step, whichever comes first.

The pull force sensors are not driven but provide a certain pull force on the piece of fabric on which a cover layer must be deposited. The tensile force is determined based on the material type. For more fragile materials, and certainly for the most fragile materials, the applicant has discovered that a calibration of the pull force sensors for each individual run after closing the machine and pumping to basic pressure improves the quality of winding and of the polymeric coating. .

Preferably, the pull force sensors are calibrated for each individual run as soon as the basic pressure is reached and for the first process step.

The deposition process preferably takes place at a speed of 0.1 to 20 m / min, e.g. 0.5 to 15 m / min, such as 1 to 10 m / min, take less than 9, 8, 7, 6 m / min, preferably 1 to 5 m / min.

Preferably the tensile force to which the fabric is wound is 0.2 to 250 kg (2 to 2500 N), more preferably 0.5 to 100 kg (5 to 1000 N), e.g. 1 to 50 kg (10 to 500 N), such as 1.5 to 25 kg (15 to 200 N), such as 1.5 to 10 kg (15 to 100 N).

Preferably, for rolls with limited outside diameter, weight and width, the unwinding zone and the winding zone are positioned at the same probability of the plasma chamber, with unwinding starting in the lower part of the winding zone and winding taking place in the upper part of the winding zone.

For heavy and / or long and / or wide rolls, e.g. 2 m wide, the take-up zone and the take-off zone positioned at different ends of the plasma chamber, e.g. the unwinding zone on the left and the winding zone on the right.

In a further aspect the invention provides a method for a piece of fabric, e.g. a textile material provided with a polymeric cover layer, wherein the method comprises providing a plasma chamber containing a plurality of electrode layers that are successively suitable within the plasma chamber, wherein at least two adjacent electrode layers are radio frequency electrode layers or grounded electrode layers; and guiding a piece of fabric between these electrode layers.

Preferably, the method comprises controlling the temperature of each radiofrequency electrode layer, e.g. from about 5 to 200 ° C, such as from about 20 to 90 ° C, more preferably from about 25 to 60 ° C, even more preferably from about 30 to 40 ° C.

Preferably, the step of controlling the temperature of each radio frequency electrode layer comprises feeding a heat controller with a liquid such as water, oil or other liquids or combinations thereof.

Preferably, the method comprises controlling the temperature of the plasma chamber, e.g. to avoid temperature differences inside the room, and to avoid cold points where the monomer can condense. For example, the door and some or all of the walls of the plasma chamber may be provided with a temperature control.

Preferably, the temperature control maintains the temperature of room temperature from about 20 ° C to 70 ° C, more preferably from about 30 to 50 ° C.

Preferably also the pump, the liquid monomer feed and all connections between these items and the plasma chamber temperature are controlled to avoid cold points where the process gas or gases can precipitate.

The method preferably comprises the step of applying a power across the radio frequency electrode layers via one or more connector plates.

The power for the plasma can be applied continuously or in a pulsed manner.

Preferably, when applied in a continuous manner in a 9000 liter chamber, the applied power is about 5 to 5000 W, more preferably about 10 to 4000 W, even more preferably about 25 to 3500 W, even more preferably, for example 30 to 3000 W, preferably still, for example 40 to 2500 W, and more preferably from 50 to 2000, 1900, 1800, 1750, 1700, 1600, 1500, 1400, 1300, 1250, 1200, 1100, 1000, 950, 900, 850, 800, 750, 700, 650, 600, 550, 500, 450, 400, 350, 300, 250, 200, 175, 150, 125, 100, 90, 80, 75, 70, or 60 W.

Preferably, when applied in a pulsed manner in a 9000 liter chamber, the applied power is about 5 to 5000 W, more preferably about 25 to 4000 W, even more preferably about 50 to 3500 W, even more preferably, for example 75 to 3000 W, most preferably still, for example 100 to 2500 W, and more preferably from 150 to 2000, 1900, 1800, 1750, 1700, 1600, 1500, 1400, 1300, 1250, 1200, 1100, 1000, 950, 900, 850, 800, 750 , 700, 650, 600, 550, 500, 450, 400, 350, 300, 250, 200, or 175 W.

When applied in pulsed power, the pulsation frequency can be selected between 100 Hz and 10 kHz, with a switching duration of about 0.05 to 50%, the optimum parameters depending on the monomer being used.

Although the applied power may seem high, a person skilled in the art will understand that a large plasma chamber, such as one with a capacity of 9000 liters, contains more and larger radiofrequency electrode layers or electrode sets compared to machines in which smaller textile sheets are treated instead of rolls. Consequently, the ability to form a uniform and stable plasma is increased. But compared to gaseous precursor monomers as described in publications, the present invention is deposited at low power. Coatings as known in the art, trimmed with gaseous precursors, require an applied power of 5000 W or more, up to 10000 W and even up to 15000 W, depending on the dimensions and the number of electrodes.

Preferably, the or each radiofrequency electrode layer generates a high frequency electric field at a frequency of 20 kHz to 2.45 GHz, more preferably from 40 kHz to 13.56 MHz, with 13.56 MHz being preferred.

Preferably a plurality of rollers is used to guide the piece of dust between the electrode layers.

As used herein, the term "adjacent electrode layers" refers to a pair of electrode layers, with one electrode layer of the pair, in use, on one side of the piece of fabric and the other electrode layer of the pair on the other side of the piece of fabric.

A further aspect of the present invention provides a method of depositing a polymeric coating on a fabric, including a textile material, the method comprising contacting a fabric with a monomer, the monomer being subjected to a plasma polymerization is subjected to low power, and wherein the monomer according to the general formula (I) is:

(I)

Where n is 2 to 6, m is 0 to 9, X and Y are H, F, Cl, Br or I, R 1 is H or alkyl or a substituted alkyl, e.g. an at least partially halo-substituted alkyl, and R 2 is H or alkyl or a substituted alkyl, e.g. an at least partially halo-substituted alkyl.

Preferably, the method comprises the step of depositing on the substance wherein the substance is unwound from a first roller on which the substance is placed, passes through the deposition zone and is rewound on a second roller.

Preferably, the method comprises the step of depositing on the substance, wherein the substance is guided between a first and a second roller.

Preferably the method comprises the step of depositing on one or both surfaces of a piece of fabric.

For depositing a cover layer, it can be advantageous to gas out the textile and to carry out an activation and / or cleaning step. By gassing out the textile that is normally wound on a roll, the basic pressures that can be achieved in the depositing apparatus are lower than without the fumigation, which leads to a better quality of the cover layer. The gassing takes place during the pumping by removing and pumping away all the moisture present in and on the surface of the textile material. The time required to gas out depends on the type of polymer that makes up the textile. Natural fibers such as cotton (cellulose) tend to absorb more moisture than synthetic fibers.

Preferably, the textile is washed out by unwinding the textile from a first roller during a first process step, after which it passes through the plasma zone, and then rewinding it back onto a second roller. Before starting the fumigation, the plasma chamber containing the roll is evacuated to a predetermined basic pressure. As soon as this basic pressure has been reached, the fumigation starts by unwinding the textile from the roll through the plasma zone without applying a power to avoid the presence of plasma in the chamber. As the pump continues to pump all the time, moisture and trapped gases such as oxygen, nitrogen, carbon dioxide, noble gases and the like are removed from the textile and away from the plasma chamber when the textile is unwound from a first roller, through the plasma zone passes without plasma and is subsequently wound on a second roller.

Depending on the nature of the substance, better outgassing can be achieved by repeating this process of unwinding and unwinding. This can be repeated several times, particularly in the case of natural fibers such as cotton and wool, which tend to absorb and retain more moisture than synthetic fibers.

If, after the outgassing step, the pressure in the chamber has fallen below a predetermined base pressure for pre-treatment or below a predetermined base pressure for deposition of the coating, the next step, resp. pre-treatment or deposition. If the predetermined basic pressure for pretreatment or deposition has not been reached, a second outgassing step is carried out by rewinding the textile from the second roller, through the plasma zone where no plasma is present, on the first roller whereby the pumping continues all the time .

If necessary, a third, fourth, fifth, etc. gassing step can be done in the same manner as described above by winding the textile back and forth.

The main advantage of this unwinding and unwinding method of gassing is that the moisture and trapped gases are removed faster than when gassing is done on a full roll of textile without unwinding but only by pumping, since the moisture and trapped gases are height of the windings of textile close to the core of the roll need longer pumping times so that they are removed than when the textile is unwound, because, for example, in most cases the moisture in these inner layers of fabric on a full roll is not sufficiently removed , not even for very long pumping times.

Preferably the outgassing takes place at a speed of 1 to 30 m / min, for example 2 to 20 m / min, such as 3 to 15 m / min, most preferably at about 5 to 10 m / min.

Preferably, the speed at which the second, third, fourth, etc., gasification step is performed is equal to or higher than the speed of the first gasification step. Whether or not the speed is increased depends on various factors, such as the composition of the fabric - whether it contains natural fibers such as cotton or wool or synthetic fibers such as a polymer or polymers -, the thickness of the fabric, the construction, etc. .

Preferably the tensile force at which the fabric is wound is equal to the tensile force at which the deposition of the cover layer takes place.

With this improved method of outgassing, a larger amount of moisture and trapped gases are removed at a reduced time, which is beneficial for both the quality of the coating and the total process time.

Pre-treatment in the form of an activation and / or cleaning and / or etching can be advantageous in the area of adhesion and cross-linking of the polymeric coating.

Adhesion of the polymeric coating with the fabric is essential to ensure good and durable coatings that are able to withstand repeated washes. In most cases, textile contains residues as a result of manufacturing processes used to produce the textile, such as dyeing, weaving, embossing, and even spinning the yarns. When a polymeric coating is deposited on such a textile, a substantial portion of the polymeric coating will bond with these residues, and during washing, a portion of these residues are removed together with the polymeric coating deposited thereon. Pre-treatment in the form of an activation and / or cleaning and / or etching removes these residues and prepares the textile for better bonding with the polymeric cover layer, whereby the durability of the textile on which a cover layer is deposited is improved, e.g. during washing.

This pre-treatment is preferably carried out with inert gases such as argon, nitrogen or helium, but more reactive gases such as hydrogen, oxygen and / or etching reagents such as CF4 can also be used. The pre-treatment is performed with continuous plasma or pulsed plasma for short residence times in the plasma zone.

The activation and / or cleaning and / or etching preferably takes place at a speed of 1 to 30 m / min, for example 2 to 20 m / min, such as 3 to 15 m / min, most preferably at about 5 to 10 m / min .

Preferably the tensile force at which the fabric is wound is equal to the tensile force at which the deposition of the cover layer takes place.

When the pretreatment is carried out in continuous mode in a 9000 liter chamber, it preferably takes place at 25 to 10000 W, more preferably at 50 to 9000 W, even more preferably at 100 to 8000 W, most preferably at 200 to 7500 W, and at preferred 250 to 7000, 6750, 6500, 6250, 6000, 5750, 5550, 5250, 5000, 4750, 4500, 4250, 4000, 3750, 3500, 3250, 3000, 2900, 2800, 2750, 2700, 2600, 2500, 2400, 2300, 2250, 2200, 2100, 2000, 1900, 1800, 1750, 1700, 1600, 1500, 1400, 1300, 1250, 1200, 1100, 1000, 950, 900, 850, 800, 750, 700, 650, 600, 550, 500, 450, 400, 350, or 300 W.

When the pretreatment is carried out in pulsed mode in a 9000 liter chamber, it is preferably at a peak power of 25 to 10000 W, more preferably of 50 to 9000 W, even more preferably of 100 to 8000 W, most preferably of 200 to 7500 W, and preferably from 250 to 7000, 6750, 6500, 6250, 6000, 5750, 5550, 5250, 5000, 4750, 4500, 4250, 4000, 3750, 3500, 3250, 3000, 2900, 2800, 2750, 2700, 2600, 2500, 2400, 2300, 2250, 2200, 2100, 2000, 1900, 1800, 1750, 1700, 1600, 1500, 1400, 1300, 1250, 1200, 1100, 1000, 950, 900, 850, 800, 750, 700, 650, 600, 550, 500, 450, 400, 350, or 300 W.

It is clear that the power and the manner in which the power is applied during the pre-treatment depends on the gas or gas mixture used, and / or on the dimensions of the chamber and / or the design, dimensions and / or number of electrodes present in the chamber .

In a first embodiment, the total deposition process comprises a single step, i.e. a deposition step, wherein neither a fumigation nor a pre-treatment is carried out before deposition of the cover layer on the textile.

In another embodiment, the total deposition process comprises three steps, each step comprising the textile being unwound, being passed through the plasma zone and being rewound, the steps comprising: a scrubbing step, a pre-treatment step such as cleaning and / or activation and / or etching with plasma; and a deposition step.

During the pre-treatment step, the unwind zone of the pre-treatment step becomes the unwind zone of the pre-treatment, and the unwind zone of the evacuation step becomes the rewind zone of the pre-treatment. During the deposition step, the pre-treatment unwind zone becomes the settling step unwinding zone and the pre-treatment unwinding zone becomes the deposition winding zone.

In a further embodiment, the total deposition process comprises two steps, each step comprising the textile being unwound, passed through the plasma zone and rewound, the steps comprising: a step for combined gasification and pre-treatment (activation and / or cleaning) and / or etching) of the textile; and a deposition step. During the combined fumigation and pre-treatment step, both processes take place at the same time.

During the deposition step, the unwinding zone of the first step becomes the unwinding zone of the deposition step and the unwinding zone of the first step becomes the winding zone of the deposition step.

Another possibility is that the substance, e.g. an item such as a garment is hung in the plasma chamber at a fixed position, the method involving depositing a polymeric coating on this material.

Preferably, R 1 is H, R 2 is H, and Y is H.

Preferably, m is 1 to 9.

Preferred examples of the monomer are acrylates and methacrylates with perfluorocarbon chains consisting of two to six carbon atoms, such as 1H, 1H, 2H, 2H-perfluorooctyl methacrylate or 1H, 1H, 2H, 2H-perfluorooctyl acrylate.

The method preferably comprises the step of using the monomer to initiate the plasma to form the polymeric coating. The advantage here is that there is no need for an additional gas to generate the plasma.

The method preferably comprises depositing a polymeric coating with a thickness of 10 to 500 nm, more preferably of 10 to 250 nm, even more preferably of 20 to 150 nm, most preferably e.g. from 30 to 100 nm, 40 to 100 nm, 40 to 90 nm. The coating can be less than 500 nm, e.g. less than 450, 400, 350, 300, 250, 200, 150, 100 nm.

The method preferably comprises depositing a polymeric coating with a variation in uniformity of less than 10%.

Preferably because the method is depositing a polymeric coating with a variation in uniformity of less than 10 ° in water contact angle and of less than 0.5 in oil repellency according to IS014419.

With the present invention, super-hydrophobic surfaces can be obtained with water contact angles of more than 100 °, such as 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119 or 120 °. The same coatings are super oil repellent with oil repellency levels of 3 or more, such as 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5 or 8, for example measured up to 6 according to IS014419, take up to 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, or 8.

Preferably the method comprises depositing a polymeric coating with a water contact angle of 100 ° or more and / or an oil repellency of level 3, 4 or more according to IS014419 at a residence time in the plasma zone of about 2 minutes or less.

Preferably, the method comprises the step of depositing a polymeric coating with a thickness of 30 nm in a residence time in the plasma zone of about 1 minute or less.

Preferably, the method comprises the step of depositing a polymeric coating with a thickness of 50 nm in a residence time in the plasma zone of about 2 minutes or less.

The method may involve the introduction of a fixed monomer flow into a plasma chamber via a monomer vapor supply system. A pressure control valve between the pump and the plasma chamber allows to control the pump flow rate so that the required process pressure in the plasma chamber is achieved.

Preferably, the pressure control valve is closed for more than 90% (that is, the effective cross-section in the supply line is reduced to 10% of its maximum value) to reduce the flow through the chamber and to allow the monomer to uniformly enter the to spread around the room.

Once the monomer vapor pressure in the chamber is stabilized, the plasma is activated by turning on one or more radio frequency electrodes.

Another possibility is to introduce monomer into the plasma chamber in a first flow sense; and changing the flow sense to a second flow sense after a predetermined time, e.g. from 10 to 300 seconds, e.g. from 30 to 240 seconds, or 40 to 180 seconds, e.g. less than 180, 170, 160, 150, 140, 130, 120, 110, 100, 90, 80, 70, 60, 50, 40, 30 or 20 seconds.

Preferably, further changing the monomer flow sense is possible, e.g. the current sentence can be changed back to the first current sentence, or to one or more other current sentences.

Preferably, the monomer enters the plasma chamber in a first flow sense for 20 to 80% of a single process time, or 30 to 70%, or 40 to 60% of the time, or 50% of the time.

Preferably, the monomer enters the plasma chamber in a second flow sense for 20 to 80% of a single process time, or 30 to 70%, or 40 to 60% of the time, or 50% of the time.

Preferably, the first and second flow lines are in substantially opposite directions. For example, during a process, the monomer can be introduced into the plasma chamber through walls or inlets substantially opposite each other.

Advantages of the inventive method include, but are not limited to, allowing one or more highly reactive monomer classes to polymerize under low power continuous plasma; generate an optimal plasma; an adaptable design of the plasma zone and the number of electrodes to optimize the process speed for improved implementation in production environment; providing a way for accurate temperature control to avoid unwanted temperature gradients; adjustable tensile force on the pull force sensors (Eng. load cells) and variable control of the rollers for optimum winding of the material; customizable design of the unwinding and rewinding zone depending on the dimensions and weight of the roll of textile material to be treated.

Advantages of the inventive polymeric cover include, but are not limited to, improved water and oil repellency of the treated fabric; improved functionality of the treated textile; improved adhesion; improved durability of treated textiles and retention of electrostatic charge over time and in case of contact with surrounding liquids such as isopropanol for electrostatically charged filtration textile, e.g. electrets.

A further aspect of the present invention provides a substance, e.g. a textile material, obtained from a polymeric coating by contacting the substance with a monomer and subjecting this monomer to a low-power plasma polymerization, wherein the monomer is of the general formula (I), and wherein n is 2 to 6, m is 0 to 9, X and Y are selected from H, F, Cl, Br, or I, and R 1 is H or alkyl, e.g. -CH 3, or a substituted alkyl, e.g. an at least partially halo-substituted alkyl, and R 2 is H or alkyl, e.g. -CH 3 or a substituted alkyl, e.g. an at least partially halo-substituted alkyl.

The fabric is preferably a piece of fabric, e.g. wrapped on a roll.

The fabric is preferably a fabric, a non-woven, a knitted fabric, a film, a foil or a membrane.

Fabrics, non-woven fabrics and knitted fabrics can have smooth surfaces or textured surfaces, such as in the case of a woven pile (pile weave) or knitted pile (pile knit).

The substance preferably contains a synthetic material, a natural material or a mixture. Examples of materials are, but are not limited to:

Synthetic: polypropylene (PP), polyethylene (PE), polyvinyl chloride (PVC), polystyrene (PS), polyphenylene sulfide (PPS), polyacrylonitrile (PAN), polyurethane (PUR), polyurea, polytetrafluoroethylene (PTFE) and expanded polytetrafluoroethylene (ePTFE) , polyester (PES) - such as polyethylene terephthalate (PET), recycled PET and polybutylene terephthalate (PBT), polyamide (PA) - such as PA6, PA66, and PA12, polyaramide, elastane (polyurethane-polyurea copolymer).

Natural and man-made: cotton, cellulose, cellulose acetate, silk, wool, etc. Mixtures: cotton / PES 50:50, PES / carbon 99: 1, recycled PES / elastane 92: 8, etc.

Fabrics and knitted fabrics can have a thickness of 50 µm to 5 mm. Non-woven fabrics can have a thickness of 5 µm to 5 mm. Films and films can have a thickness of 20 µm to 1 mm.

The polymeric cover layer preferably has a thickness of 10 to 500 nm, e.g. from 10 to 250 nm, e.g. from 30 to 100 nm, e.g. from 40 to 90 nm.

Preferably, the polymeric coating comprises super-hydrophobic and / or super-oil-repellent properties. The superhydrophobic polymeric cover layer preferably has a water contact angle of 100 ° or more, such as 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119 or 120 °. The super oil repellent polymeric coating preferably has an oil repellency level of 3 or more, such as 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5 or 8, e.g. measured up to 6 according to IS014419, take up to and with 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, or 8.

In a further aspect, the invention provides for the use of a monomer to form a polymeric coating on a fabric, e.g. a textile material, when monomer is brought into contact with the substance and the monomer is subjected to a low-power plasma polymerization, wherein the monomer is according to the general formula (I), and wherein n is 2 to 6, m is equal at 0 to 9, X and Y are selected from H, F, Cl, Br, or I, and R 1 is H or alkyl, e.g. -CH 3, or a substituted alkyl, e.g. an at least partially halo-substituted alkyl, and R 2 is H or alkyl, e.g. -CH 3 or a substituted alkyl, e.g. an at least partially halo-substituted alkyl.

In order for the invention to be better understood, it will now be described by way of example with reference to the accompanying drawings, in which:

Figure 1 shows a schematic representation of a roll-to-roll plasma deposition device;

Figure 2 shows a first electrode arrangement according to the professional knowledge;

Figure 3 shows a second electrode arrangement according to the professional knowledge;

Figure 4 shows a first electrode arrangement according to the present invention;

Figure 5 shows a second electrode arrangement according to the present invention;

Figure 6 shows a third electrode arrangement according to the present invention;

Figure 7 shows a fourth electrode arrangement according to the present invention; and

Figure 8 shows front view (a), side view (b) and end (c) of a radio frequency electrode layer.

Referring to Figure 1, a roll-to-toll plasma deposition apparatus, designated 1, will be described. The device 1 comprises a plasma chamber 10, a first compartment 12 and a second compartment 14. The first 12 and second 14 compartments are the unwinding and winding compartments disposed at both ends of the plasma chamber. These compartments are known to people in the field and are not described in further detail here.

The plasma chamber 10 contains a sequence of electrode layers RF and M, the arrangement of the electrode layers being further discussed in detail in Figure 4. The plasma chamber 10 further comprises a series of upper 101 and lower 102 rollers and tensile force sensors around a textile piece 16, between the electrode, lay RF, M of a first roll 120, placed in the first compartment 12, to guide / wrap on a second roll 140, placed in the second compartment 14.

Schematic representations of electrode layer arrangements according to the professional knowledge are shown in Figure 2 and Figure 3. The simplest arrangement is shown in Figure 2, wherein a radiofrequency electrode layer and a grounded electrode layer are placed next to each other. This arrangement can be noted as M / RF, where "M" indicates a grounded electrode layer, "RF" a radiofrequency electrode layer, and "/" the space where the textile material 16 passes. Upper 101 and lower 102 rollers are positioned to guide a piece of textile material 16 from a first roll 120 to another roll 140. In use, and when an electromagnetic field is applied to the radio frequency electrode layer RF, plasma is generated between the radio frequency electrode layer RF and the mass electrode layer M. Such a plasma is known as primary plasma. When monomer is present in plasma chamber 10, this results in a polymeric coating that is deposited on the surface of the textile piece 16 that faces the radiofrequency electrode layer RF, resulting in a textile material piece 16 that has a uniform polymeric coating on a single side from the surface.

Figure 3 shows another arrangement in which additional radiofrequency electrode layers RF and grounded electrode layers M are positioned side by side. This settlement can be noted schematically as M / RF / M / RF / M. Again, primary plasma is generated between a radiofrequency electrode layer RF and a ground electrode layer M such that a polymeric cover layer is applied to the surface of the textile material piece 16 facing the radiofrequency electrode layers RF. The textile material 16 makes four passages and at each passage a polymeric coating is deposited on the same side of the textile material, facing the radiofrequency electrode layers, resulting in a textile material 16 with a uniform polymeric coating deposited on one side.

In a first embodiment according to the invention, the electrode arrangement consists of ten electrode layers in a sequence as shown in Figure 4. This arrangement can be schematically noted as M / RF / M / RF / M / M / RF / M / RF / M and represents the arrangement of Figure 1. In use, and when an electromagnetic field is applied to the radiofrequency electrode layers, plasma is generated between the electrode layers. A primary plasma arises between a radio frequency electrode layer RF and a mass electrode layer M. Therefore, although it is clear that the textile material 16 makes nine passages between electrode layers, only the first four and the last four passages are through primary plasma zones. Thus, during the first four passages, monomer is polymerized on a first side of the textile material 16, while during the last four passages, monomer is polymerized on the other side of the textile material 16, resulting in a textile material 16 with a uniform polymeric coating on both sides . During the fifth passage, no to a minimum amount of monomer is deposited on the textile material 16.

Figure 5 shows a second, simplified embodiment of the invention in which the electrode configuration consists of four electrode layers placed according to the schematic notation M / RF / RF / M. In use, and when an electromagnetic field is applied to the radiofrequency electrode layers, plasma is generated between the electrode layers. A primary plasma arises between a radio frequency electrode layer RF and a grounded electrode layer M. Therefore, although it is clear that the textile material 16 makes three passages between electrode layers, only the first and the last (third) passage through primary plasma zones are. Thus, during the first passage, monomer is polymerized on a first side of the textile material 16, while during the last (third) passage monomer is polymerized on the other side of the textile material 16, resulting in a textile material 16 with a uniform polymeric coating on both sides. During the second passage, no to a minimum amount of monomer is deposited on the textile material 16.

In a third embodiment, the electrode layers can be arranged according to the schematic representation RF / M / M / RF. In use, and when an electromagnetic field is applied to the radiofrequency electrode layers, plasma is generated between the electrode layers. A primary plasma arises between a radio frequency electrode layer RF and a grounded electrode layer M. Therefore, although it is clear that the textile material 16 makes three passages between electrode layers, only the first and the last (third) passage through primary plasma zones are. Thus, during the first passage, monomer is polymerized on a first side of the textile material 16, while during the last (third) passage monomer is polymerized on the other side of the textile material 16, resulting in a textile material 16 with a uniform polymeric coating on both sides. During the second passage, no to a minimum amount of monomer is deposited on the textile material 16.

The applicant has surprisingly discovered, also through tests such as water contact angles and oil repellency, that the polymeric cover layer has a better uniformity when the grounded electrode layers are placed at the outer positions, as described in the first and second embodiment.

In order to provide both sides of the fabric with a cover layer, the applicant has discovered that it is important to have a pair of electrode layers of the same type, e.g. grounded electrode layers as described in the first or third embodiment, or radiofrequency electrode layers as described in the second embodiment. These inventive arrangements result in changing the side of the textile material 16 on which the polymeric cover layer is deposited.

In further embodiments, additional arrangements may be considered, such as RF / M / RF / RF / M / RF or M / RF / M / M / RF / M. In these arrangements, it is clear that the textile material 16 makes five passages between the electrode layers: the first, second, fourth, and fifth passages are through primary plasma zones. Consequently, during the first and second passages, monomer is polymerized on a first side of the textile material 16, while during the fourth and fifth passages, monomer is polymerized on the other side of the textile material 16, resulting in a textile material 16 with a uniform polymeric coating on both sides. During the second passage, no to a minimum amount of monomer is deposited on the textile material 16.

Similarly, additional embodiments may be considered, with additional electrode layers added to the sequence, e.g. M / RF / M / RF / RF / M / RF / M or RF / M / RF / M / M / RF / M / RF or RF / M / RF / M / RF / RF / M / RF / M / RF or M / RF / M / RF / M / M / RF / M / RF / M or M / RF / M / RF / M / RF / RF / M / RF / M / RF / M or RF / M / RF / M / RF / M / M / RF / M / RF / M / RF etc. With increasing number of electrode layers, the number of passages in the primary plasma zone also increases. In this way, it is possible to control the thickness of the resulting polymeric cover layer by providing more or fewer electrode layers in the sequence. Furthermore, by increasing the number of electrode layers in the sequence, it is possible to also increase the speed at which the textile material 16 is passed through the plasma chamber without compromising on the quality of the polymeric cover layer.

In a further embodiment, shown in Figure 6, the electrode layers are suitable as follows: M * RF * M / M * RF * M, wherein "M" denotes a grounded electrode layer, "RF" a radiofrequency electrode layer, "* 'a primary plasma zone and' / 'the space where the textile material 16 passes. In this embodiment, the plasma chamber 10 comprises a first electrode set (M * RF * M) and a second electrode set (M * RF * M), wherein the first and the second electrode set consist of electrode layers and wherein each electrode set consists of two grounded electrode layers M and a single radio frequency electrode layer RF. It is clear that in this embodiment the textile material 16 makes a single passage between the electrode sets (M * RF * M).

Although the inventors do not wish or wish to be bound by any particular theory, it is to be understood that the plasma generated between electrode sets (M * RF * M) of this embodiment cannot be categorized as a pure primary or a pure secondary plasma . The inventors rather regard the plasma between the electrode sets (M * RF * M) as a new hybrid form of plasma, which is strong enough to be activated and remain inflamed and at the same time gentle enough not to remove the reactive monomers to break. During the only passage, monomer is polymerized on both sides of the textile material piece 16, resulting in a textile material 16 with a uniform polymeric coating on both sides.

The process speed can be increased by placing additional electrode sets (M * RF * M) in the plasma chamber 10, for example third, fourth, fifth and sixth electrode sets (M * RF * M), and so on. For example, when a third electrode set (M * RF * M) is added, a cover layer is deposited on both sides of the textile material 16 in two passes, e.g. M * RF * M / M * RF * M / M * RF * M, or RF * M * RF / RF * M * RF / RF * M * RF.

Figure 7 shows an example of an electrode arrangement that contains six consecutive electrode sets (M * RF * M). In contrast to Figure 1, Figure 7 involves unwinding and unwinding in the same zone on the same side of the plasma chamber.

Figure 8 shows a radio frequency electrode layer RF in front view (a), side view (b) and the end (c). The radio frequency electrode layer RF consists of a generally flat structure formed by folding tube 21. Tube 21 may consist of a plurality of sections that are joined together with connectors 27. The tube 21 is typically made of a conductive metallic material such as aluminum, stainless steel, or copper. The tube 21 is hollow allowing a heat regulator fluid to pass through the electrode layer RF so that the plasma can be adjusted to a predetermined temperature. Tube 21 consists of a series of bends 22 that are formed at regular distances. The tube 21 bends about 180 ° around itself at bend 22. The tube 21 has a diameter of about 10 mm and a wall thickness of about 2 mm. The distance between tube 21 before and after each bend 22 is approximately 5 times the diameter of the bend 21.

Tube 21 is bent at each end to form pieces 25 and 26 that are perpendicular to the flat structure of the electrode. The ends 25, 26 can be connected to a liquid or outlet channel. Ends 25, 26 can also be connected to the ends of adjacent electrode layers.

The radio frequency electrode layer RF further comprises a pair of connection plates 23, 24 which are connected to the front and rear sides of the electrode layer 20 at the bends 22. The connection plates 23, 24 provide means for the radio frequency electrode layer RF in the vacuum chamber 11 and provide electrical contacts to apply power to the radio frequency electrode layers RF.

A grounded electrode layer M (not shown in detail) typically consists of a flat plate made in aluminum.

An example of the successive steps of depositing a polymeric coating on a roll of fabric is the following: 1. A roll of fabric 120 to be treated is placed in a first compartment 12 of device 1; 2. The free end of the fabric 16 is guided, manually or automatically, over the rollers 101, 102 within the plasma chamber 10 and then attached to an empty roll 140 in a second compartment 14; 3. The plasma chamber 10 is closed, and the electrodes mounted on the moving part of the machine are slid between the guide rollers 101, 102 (and thus also between the textile material 16); 4. The plasma chamber 10 is sealed and is evacuated to a required, predetermined basic pressure; 5. The pull force sensors are calibrated for optimum process flow; 6. The gas inlet valve is opened and liquid monomer vapor is introduced into the plasma chamber 10 in a controlled manner at a controlled flow rate; 7. An electromagnetic field is applied to the radio frequency electrode layers RF and a continuous plasma at low power is generated; 8. Power is applied to rollers 101, 102 of apparatus 1 to unwind the textile material 16 from the first roll 120 and to unwind on the second roll 140, the layers RF, M or electrode sets between unwinding and winding up between the electrode M * RF * M, RF * M * RF passes with a polymeric coating deposited on each side of the fabric 16; 9. As soon as all the textile material 16 is provided with a polymeric cover layer, the electromagnetic field is switched off and the plasma chamber 10 is vented to atmospheric pressure.

A second example of the steps to deposit a polymeric coating on a roll of textile material, e.g. in a 9000 I chamber, is as follows: 1. A roll of fabric 120 to be treated is placed in a first compartment 12 of device 1; 2. The free end of the fabric 16 is guided, manually or automatically, over the rollers 101, 102 within the plasma chamber 10 and then attached to an empty roll 140 in a second compartment 14; 3. The plasma chamber 10 is closed, and the rollers and all the textile (on roll in the unwinding zone, the free end on a roll in the winding zone, and the textile guided between the guide rollers), which are mounted on the moving part of the machine, are slid between the electrode layers or electrode sets; 4. The plasma chamber 10 is sealed and is evacuated to a required, predetermined base pressure for outgassing and pre-treatment; 5. The pull force sensors are calibrated for optimum process flow; 6. The gas inlet valve is opened and the inert gas for pre-treatment, e.g. cleaning and / or fumigation and / or etching, which is combined with further fumigation of the textile before depositing a cover layer, is introduced into the plasma chamber 10; 7. An electromagnetic field is applied to the radio frequency electrode layers RF and a plasma is generated; this plasma can be applied both continuously and in a pulsed manner, the choice of the plasma method depending on the required power, on the gas or gases used for the pre-treatment, and / or on the dimensions and design of the plasma machine and / or of the textile material to be treated 16; 8. Power is applied to rollers 101, 102 of apparatus 1 to unwind the textile material 16 from the first roll 120 and to unwind on the second roll 140, the layers RF, M or electrode sets between unwinding and winding up between the electrode M * RF * M, RF * M * RF passes where moisture is further removed from the material 16 and where both sides of the material 16 undergo the pretreatment; 9. Once the entire textile material 16 has been gassed and pretreated, the electromagnetic field is turned off and the plasma chamber 10 is further evacuated to the required lower base pressure for the deposition of a polymeric coating; 10. The gas inlet valve is opened and liquid monomer vapor is introduced into the plasma chamber 10 in a controlled manner at a controlled flow rate; 11. An electromagnetic field is applied to the radio frequency electrode layers RF and a low power plasma is generated; this plasma can be applied both continuously and in a pulsed manner, the choice of the plasma method depending on the power required, the monomer used for the pre-treatment, and / or the dimensions and design of the plasma machine and / or or of the textile material to be treated 16; 12. Power is applied to rollers 101, 102 of device 1 to unwind the textile material 16 from roll 140 and to wind up on the other roll 120, with the layers of RF, M or electrode sets M between unwinding and winding up between the electrode layers. * RF * M, RF * M * RF passes with a polymeric coating deposited on each side of the fabric 16; 13. As soon as all the textile material 16 is provided with a polymeric cover layer, the electromagnetic field is switched off and the plasma chamber 10 is vented to atmospheric pressure.

Example 1

A first experiment was performed on small rolls of textile material for use in filtration applications before proceeding to scale-up at production level. The textile consists of a non-woven fabric of synthetic material made of polymer fibers. The roll was 1000 m long and 1.1 m wide.

The process parameters are summarized in Tables 1 and 2.

Table 1

Table 2

The resulting textile with a polymeric coating according to Table 1 showed good water and oil repellency and also efficient filtration. It was decided to scale this process up to production level.

The resulting water and oil repellency of the textiles treated according to Table 2 are lower than for the textiles treated according to Table 1. Nevertheless, it was decided to also scale this process up to production level.

Example 2

The processes of Example 1 were used on a larger scale. The textile material remained the same as in Example 1. The roll was 10000 m long and 1.1 m wide.

The process parameters are summarized in Tables 3 and 4.

Table 3

Table 4

The resulting textile with coating according to Table 3 shows good water and oil repellency and also efficient filtration. The resulting water and oil repellency of the fabric treated according to Table 4 are lower than for the fabric treated according to Table 3.

Results

Oil repellency

Examples 1 and 2 show that continuous mode plasma polymerization at low power gives a better performance than pulsed plasma polymerization. This is demonstrated by the oil repellency tested according to ISO 14419.

The results are shown in Table 5, and show that the oil repellency for continuous mode coatings on A4 sheets is higher than for pulsed coatings, the effect being more pronounced for short treatment times, e.g. two minutes.

Table 5: Oil repellency for continuous and pulsed plasma coatings. Filtration efficiency

The filtration efficiency for standard filtration media and filtration media treated according to the present invention were tested at three different levels of "High Efficient Particle Retaining" filter elements (Eng. HEPA - or High Efficiency Particulate Arresting filter elements), levels F7, F8 and F9 . Levels F7, F8 and F9 are indications given to secondary filter elements, depending on the efficiency that they should achieve according to BS EN 779. The required efficiency in use ("middle efficiency", depends on the particle size to be filtered.

For 0.4 μιτι particles, the middle efficiency for F7 filters must be 80 - 90%. For F8 filters this should be 90 - 95%, and for F9 filters this should be more than 95%.

The filtration media used in this test is charged, i.e. an electret is formed, and can be used in heating, ventilation, and air conditioning systems (HVAC systems).

The initial and medium efficiency for 0.4 μιτι pore size is measured according to the standard European air filter test BS EN 779, both for standard filtration media and filtration media treated according to the invention, and this in charged and discharged form. The filtration media is discharged by contacting it with isopropanol.

The initial filtration efficiency is the efficiency of a clean, brand new filter element. It is evident that once the filter is in use, its pores become blocked by the filtered particles, increasing efficiency over time. The initial efficiency is therefore the minimum efficiency.

The results for F7 filter elements are shown in Table 6. To pass the test, an average efficiency of 80 to 90% and an initial efficiency of 35% or more are required.

Table 6

Table 6 clearly shows that the initial filtration efficiency for charged filter elements with a coating according to the present invention is higher than for standard filter elements. After the discharge of the filter elements, the initial and average efficiency for standard filters drops enormously, while the plasma-treated filter elements show no decrease in terms of average efficiency and only a minimal decrease in initial efficiency.

The results for F8 filter elements are shown in Table 7. To pass the test, an average efficiency of 90 to 95% and an initial efficiency of 55% or more are required.

Table 7

It is clear from Table 7 that the initial filtration efficiency for charged filter elements with a coating according to the present invention is higher than for standard filter elements. After discharge of the filter elements, the initial and average efficiency for standard filters drops, while the plasma treated filter elements show an increase in terms of average efficiency and initial efficiency.

The standard filter elements do not achieve the required average efficiency of 90 - 95%, while the plasma-treated filter achieves this, both in charged and in discharged form.

The standard filter elements also do not achieve the required initial efficiency of 55%, while the plasma-treated filter elements do, both in charged and in discharged form.

The filtration efficiency is improved for discharged filter elements by depositing an inventive coating on it. After discharge with isopropanol, the coating is still present on the filter element, thereby avoiding a decrease in efficiency.

Penetration of dispersed oil particles (DOP)

Respiratory masks made from five layers of melt-spun polypropylene (PP) non-fabric of 15 to 30 g / m 2 are electrostatically charged after deposition of a cover layer according to Example 1. The evaluation of the penetration of the DOP particles is done by means of. a Certitest 8130 device that loads the textile with 200 mg of DOP particles. The results are shown in Table 8.

Table 8

It is clear from Table 8 that the plasma treated materials score much better than the untreated reference materials. The initial penetration is approximately 3 times less; the penetration after 10 to 30 minutes is 5 to 6 times less. The filtration efficiency for oily particles is thus clearly improved by providing the materials with an inventive coating.

Filtration efficiency

Diesel filters made from 1 to 2 mm thick 500 g / m2 non-woven polyethylene terephthalate (PET) are provided with an inventive coating according to Example 2.

Efficiency is tested by immersing the filter elements in water for 22 hours, followed by dripping in a vertical position for a certain time. The weight gain is calculated and compared with untreated reference materials. The results are presented in the following graph:

Table 9

The graph clearly shows that the untreated reference material absorbs a large volume of water, about 1800% weight gain after 1 minute of dripping.

Samples with an inventive coating show extremely low water absorption, less than 10% weight gain after dripping out for 1 minute.

Washability

Three different polyester fabrics were treated with a low pressure plasma process according to Table 3 of Example 2, and were subsequently washed according to ISO 15797 (2002). One complete wash cycle consists of the following steps: 1. Washing at 60 ° C with 20 g of IPSO HF 234 without optical brightener per kilogram of dry weight; 2. Dry in the tumble dryer; 3. Heat press at 180 ° C {e.g. ironing).

Five wash cycles were performed, one after the other, after which the oil repellency was measured according to ISO 14419 and a spray test was carried out according to ISO 9073 - hatch 17 and ISO 4920.

After this, five additional wash cycles were performed and the oil repellency was measured again and a spray test was performed.

The oil repellency as a function of the number of wash cycles is presented in Table 10, the spray results as a function of the number of wash cycles in Table 11.

Table 10

Table 11

In an additional example, another polyester fabric was treated with and without a pre-treatment for the deposition step. The process without pre-treatment was carried out according to Example 1. The process parameters for the pre-treatment process are summarized in Table 12.

Table 12

After depositing the coatings, the textile samples were washed according to ISO 15797 (2002). One complete wash cycle consists of the following steps: 1. Washing at 75 ° C with 20 g of IPSO HF 234 and without optical brightener per kilogram of dry weight; 2. Dry in a drying cabinet.

After one wash cycle the oil repellency was measured according to ISO 14419 and a spray test was carried out according to ISO 9073 - hatch 17 and ISO 4920. After this, four additional wash cycles were performed after which the same evaluations were performed (values after 5 wash cycles). Subsequently, five additional wash cycles were performed and the same evaluations were performed (values after 10 wash cycles).

The oil repellency as a function of the number of wash cycles is shown in Table 13. Table 14 shows the evolution of the spray test results as a function of the number of wash cycles.

Table 13

Table 14

Tables 13 and 14 clearly show that the textile samples that had undergone pretreatment before the deposition step had a better score and had a better durability than the textile samples that had not received pretreatment. The improvement is most evident in the spray tests where the water repellency is tested. The difference in oil repellency is visible after 10 washes, as shown in Table 13.

After 20 washing cycles, the pre-treated textile still has an oil repellency of level 3.

Sustainability in abrasion

A low pressure plasma coating according to Example 2 was deposited on three different polyester fabrics, after which a Martindale abrasion test was performed. Since an evaluation was subsequently carried out via a spray test, larger samples than usual were used and the set-up was slightly adjusted.

A standard wool fabric was pressed against a plasma-treated PES fabric with a force of 9 kPa. 5000 abrasion cycles were performed, after which the oil repellency was measured according to ISO 14419 and a spray test according to ISO 9073 - hatch 17 and ISO 4920 was performed. After this 5000 additional rotations were carried out and the same evaluations were carried out.

Table 15 shows the oil repellency as a function of the number of Martindale abrasion cycles and Table 16 shows the spray test results as a function of the number of Martindale abrasion cycles.

Table 15

Table 16

Claims (20)

Conclusions A plasma chamber for depositing a polymeric coating on a piece of fabric, e.g. a textile material, wherein the plasma chamber comprises a plurality of electrode layers, each having a generally flat (planar) or plate-shaped shape, successively arranged within the plasma chamber, wherein at least two adjacent electrode layers are radio frequency electrode layers or grounded electrode layers. A plasma chamber according to Claim 1 comprising at least two pairs of electrode layers, wherein the outer pair of electrode layers are either grounded electrode layers or radiofrequency electrode layers. A plasma chamber according to any one of Claims 1 and 2, comprising a first electrode set and a second electrode set, the first and second electrode set arranged on either side of a passage for receiving a substance. A plasma chamber according to Claim 3, wherein one or both of the first and second set of electrodes consists of an inner electrode layer and a pair of outer electrode layers. A plasma chamber according to Claim 4, wherein either the inner electrode layer is a radio frequency electrode layer and the outer electrode layers are grounded electrode layers, or the inner electrode layer is a grounded electrode layer and the outer electrode layers are radio frequency electrode layers. A plasma chamber according to any one of Claims 1 to 5, wherein the radiofrequency electrode layer or layers contain a heat controller. A plasma chamber according to any one of Claims 1 to 6, wherein the plasma chamber contains a plurality of rollers when used to guide a piece of dust between the electrode layers. A plasma chamber according to any of Claims 1 to 7, further comprising one or more compartments, wherein the or each compartment is provided to receive one or more rolls of dust. A plasma chamber according to Claim 7 or Claim 8 wherein the rollers are arranged and arranged to wind the fabric to be unwound and wound up at a speed between 0.1 m / min and 20 m / min. A plasma chamber according to any one of Claims 7 to 9, wherein rolls can be unwound and wound at speeds between 1 m / min and 5 m / min. A plasma chamber according to any one of Claims 7 to 10, wherein the rollers can be driven individually and can be adjusted independently of each other. A plasma chamber according to any one of Claims 7 to 11, wherein the rollers can be cooled or warmed up so as to contribute to a substantially more uniform temperature in the plasma chamber thereby avoiding condensation of the monomer in the plasma chamber. A plasma chamber according to Claim 12, wherein the cooling or heating is done by means of. a liquid, e.g. water or oil. A plasma chamber according to Claim 13, wherein the rollers can be heated between 20 ° C and 85 ° C. A plasma chamber according to any one of Claims 1 to 14, which includes one or more pull force sensors that can be calibrated once a predetermined low base pressure is reached and is started before the first process step. A plasma chamber according to Claim 15, wherein for each individual deposition run the pull force sensors are calibrated as soon as the basic pressure is reached and before the first processing step is started or the unwinding or unwinding of the substance is started, e.g. for outgassing, or before the gas inlet is opened and the electromagnetic field is turned on for pre-treatment, or before the gas inlet is opened and the electromagnetic field is turned on before the deposition step, whichever comes first. A plasma chamber according to Claim 15 or Claim 16, wherein, in use, the tensile force to which the fabric is wound is between 0.2 and 250 kg (2 to 2500 N). 17. A method of depositing a polymeric coating on a piece of fabric, e.g. a textile material, the method comprising providing a plurality of electrode layers successively within the plasma chamber, wherein at least two adjacent electrode layers are radiofrequency electrode layers or grounded electrode layers; and lead a piece of dust between these electrode layers. A method according to Claim 18, wherein guiding a piece of fabric between the electrode layers uses a plurality of rollers. A piece of fabric on which a polymeric coating is deposited, using a plasma chamber according to any of Claims 1 to 17. A piece of fabric on which a polymeric coating is deposited, using a method according to any one of Claims 18 to 19.