TW201311365A - Surface coatings - Google Patents

Abstract

A method of forming a liquid repellent coating on a surface of a substrate, where the surface is exposed to a monomer in a plasma deposition process under conditions that maintain the monomer in situ for a period of time to allow a polymeric layer to form on the surface, wherein the conditions comprise at least one cycle of varying pressure.

Description

Surface coating

The present invention relates to a surface coating, in particular to a method of making an oil and water repellent surface; and a coated article obtained thereby.

It is known to apply water and oil repellent coatings by a number of different methods. Such coatings typically comprise a fluorocarbon chain wherein the degree of oil repellency and water repellency is a function of the number and length of fluorocarbon groups or moieties that are suitable for the available space.

Plasma deposition techniques have been used quite extensively to deposit polymer coatings on a range of surfaces. This technique is considered to produce a clean and dry technique with minimal waste compared to conventional wet chemical methods. Using this method, a small organic molecule that undergoes an ionizing electric field under low pressure conditions produces a plasma. When this is done in the presence of the substrate, the ions, free radicals and excitation molecules of the monomers contained in the plasma are polymerized in the gas phase and reacted with the growing polymer film on the substrate. Conventional polymer synthesis tends to produce structures containing repeating units that are very similar to the monomer species, while polymer networks produced using plasma can be extremely complex.

U.S. Patent No. 6,551,950 discloses the use of plasma polymerization for the formation of oil-repellent or water-repellent surfaces using long chain hydrocarbons and fluorocarbons.

Applicants have discovered that coating quality and deposition efficiency can be improved by increasing the residence time of the monomer in the processing chamber.

The residence time is the average amount of time that the particles experience in a particular system. The dwell time can be defined by the following equation: τ = C / Q [1] Where τ is the residence time, C is the capacity of the treatment chamber, and the Q system gas passes through the flow rate of the system under the pressure of the chamber.

As can be seen from the above equation, the increase in chamber size results in an extended residence time for any particular gas flow rate. Similarly, the slower the gas flow rate, the longer the residence time. Therefore, slow flow rates and large chambers will result in long residence times.

The longer the molecule stays in the chamber, the more likely it will be to undergo deposition methods (such as polymerization) and adhesion to the surface.

A first aspect of the present invention provides a method of forming a liquid repellent coating on a surface of a substrate, the method comprising: exposing the surface to the surface in a plasma deposition method while maintaining the monomer in situ for a period of time The monomer is such that a polymer layer is formed on the surface, wherein the conditions include at least one cycle of varying pressure.

The variable pressure cycle is used to increase the residence time during which the monomeric molecules are distributed throughout the processing chamber. This is because the cycle maintains the pressure within the optimum range. It may be desirable to maintain the chamber within an optimum pressure range to maximize polymerization.

Variable pressure cycling is used to increase coating uniformity, reduce processing time, and use less monomer to prepare a coating of a particular thickness compared to coating under static pressure.

The processing chamber may have a valve such as an exhaust valve that is in a closed state during the introduction of the monomer. The exhaust valve can be adjusted to open, close or partially open.

The at least one cycle can include continuously introducing monomer into the processing chamber (e.g., by injection) and allowing pressure to rise. Can be from there at the end of each cycle The chamber exhausts the exhaust gas.

At least a portion of the processing chamber may be evacuated at the beginning of each cycle to achieve a low pressure that is most suitable for forming a polymeric coating.

When the gas is exhausted at the end of each cycle, the exhaust gas such as water vapor can be discharged without affecting the low pressure achieved at the beginning of the cycle.

While keeping the exhaust valve of the chamber closed during the process ensures that optimal pressure can be easily achieved, the combination of monomer input and degassing from the treated product causes the pressure in the chamber to gradually increase until it exceeds an optimum level. Conversely, if the gate remains open during the process, the degassed product can be effectively removed; this allows the pressure to be reduced to an optimum level. However, a significant amount of input monomer will only flow through the chamber without undergoing polymerization. The use of a variable pressure cycle allows undesired outgassing products to exit the chamber, but after venting, the gate is closed to return the chamber to the lower end of the optimal pressure range. It is important to close the gate at a particular point in the cycle to keep the monomer in place (increasing its residence time) so that polymerization can occur.

The at least one varying pressure cycle can include a time based cycle. For example, the chamber may be at least partially evacuated after a predetermined period of time in each cycle. The time cycle is particularly advantageous because it allows the monomer to remain in place to increase residence time, which helps to improve the coating process.

At least one cycle of the varying pressure can include a pressure based cycle. For example, if the pressure is outside the optimum range, the processing chamber can be at least partially evacuated. The processing chamber can include a pressure sensor to determine the pressure within the chamber. The exhaust valve from the process chamber can be adjusted using feedback from the pressure sensor. For example, if the pressure falls below the optimal range, the row can be closed. The valve, and if the pressure rises above the optimal range, the exhaust valve can be opened.

Pressure-based systems are suitable for low outgassing products such as hearing aids and mobile phones because they produce long periods of circulation within the required pressure range. For high degassing products such as shoes, the pressure based cycle can be too short. However, a time-based cycle can be designed to allow the cycle to have a good length, provide a good residence time for the monomer while still maintaining near optimum pressure.

The variable pressure can be maintained below the maximum pressure. For example, the maximum pressure can be equal to or lower than 150 mTorr. Suitably, the maximum pressure can be equal to or lower than 125 mTorr.

Each cycle can be between 45 and 75 seconds. Each cycle can be about 60 seconds.

The method can include exposing the surface to a cycle of two or more varying pressures, and in particular up to four cycles. The two or more cycles can include from 5 to 12 cycles. Alternatively, the two or more cycles may include 8 or 9 cycles.

In one embodiment, the deposition method is a gas method. The deposition method can be a plasma process, such as a plasma polymerization process.

When the deposition method is a plasma polymerization method, the coating can be applied using pulsed plasma.

The liquid repellent coating can include an oil or water repellent coating.

The polymer layer can be homogeneous. However, it may also be advantageous to form a non-uniform polymer layer, such as when the coating is used in a bioarray.

The liquid repellent coating is suitable for a range of substrates (eg fabric, gold) The surface of a genus, glass, ceramic, paper or polymer substrate. Such as clothing (including footwear), laboratory consumables (including pipette tips), filters, electronic devices (including mobile phones, audio devices, laptops and hearing aids), microfluidic devices and photovoltaic modules Articles such as solar panels can be suitably treated using the method of the invention.

The plasma polymer is typically produced by subjecting the coating forming precursor to an ionizing electric field under low pressure conditions. Deposition occurs when excited species (free radicals, ions, excited molecules, etc.) generated by the action of the precursor by the electric field are polymerized in the gas phase and reacted with the surface of the substrate used to form the grown polymer film.

Plasmas suitable for use in the methods described herein include unbalanced plasmas such as those produced by radio frequency (RF), microwave or direct current (DC). As is known in the art, they can be operated at or below atmospheric pressure. However, in particular, they are generated by radio frequency (RF).

Various forms of equipment can be used to produce gaseous plasma. These typically include a vessel or plasma chamber in which plasma can be produced. Specific examples of such devices are described in, for example, WO 2005/089961 and WO 02/28548, but many other conventional plasma generating devices can also be used.

Typically, the item to be treated is placed in a plasma chamber together with the gaseous material to be deposited, causing a glow discharge in the chamber and applying a suitable voltage (which may be pulsed).

The gas used in the plasma may contain only monomeric compound vapor, but it may be combined with a carrier gas, specifically an inert gas such as helium or argon. In particular, helium is a preferred carrier gas because it allows the monomer to The cracking is minimized.

When used as a mixture, the relative amount of the monomer vapor to the carrier gas is suitably determined according to the procedures conventional in the art. The amount of monomer added will depend to some extent on the nature of the particular monomer used, the nature of the substrate being processed, and the size of the plasma chamber. Typically, the monomer is delivered at a level of from 50 to 600 mg/min (e.g., a rate of from 100 to 150 mg/min) in the case of a conventional chamber. The carrier gas (e.g., helium) is suitably delivered at a constant rate (e.g., at a rate of 5 to 90 sccm (e.g., 15 to 30 sccm). In some cases, the ratio of monomer to carrier gas will range from 100:1 to 1:100, such as from 10:1 to 1:100, and specifically from about 1:1 to 1:10. The precise ratio chosen will ensure the flow rate required to achieve the method.

In some cases, an initial continuous power plasma can be applied to the chamber for, for example, 0.5 to 10 minutes, such as about 4 minutes. This can be used as a surface pretreatment step to ensure that the monomer itself readily adheres to the surface such that when polymerization occurs, the coating "grows" on the surface. This pretreatment step can be carried out only in the presence of an inert gas prior to introduction of the monomer into the chamber.

The plasma is then suitably converted to a pulsed plasma, at least in the presence of the monomer, to allow polymerization to proceed.

In all cases, glow discharge is suitably initiated by the application of a high frequency voltage (e.g., 13.56 MHz). Electrodes are suitably used to apply this voltage, which may be located inside or outside the chamber, but in the case of larger chambers.

Suitably, the gas, vapor or gas mixture is supplied at a rate of at least 1 standard cubic centimeters per minute (sccm) and preferably from 1 to 100 sccm.

In the case of monomer vapors, this is suitably supplied at a rate of from 80 to 300 mg/min (e.g., about 120 mg/min) depending on the nature of the monomer, and a pulsed voltage is applied simultaneously.

Gas or vapor can be pumped or pumped into the plasma zone. In particular, when a plasma chamber is used, gas or vapor can be drawn into the chamber due to a decrease in chamber pressure caused by the use of an air pump, or can be pumped or injected into the chamber as is common in liquid operation. indoor.

The polymerization is suitably effected using a vapor of the compound of formula (I) which is maintained at a pressure in the range of from 40 to 150 mTorr, suitably from about 80 to 120 mTorr.

The applied electric field suitably has a power of 0.2 w to 20 w, more preferably about 2 w (applied in the form of a pulsed field). These power systems are suitable for chambers with a volume of 50 cm ³ . For larger or smaller chambers, suitable power can be used that provides the same power density. In the case of depositing polymer layers, such pulses are suitably applied in a sequence that produces very low average power, suitably at up to 10% duty cycle (i.e., on: off ratio up to 10%). More suitably, the duty cycle is from 0.1% to 1%. These turn-on pulses can be longer or shorter.

An electric field of from 30 seconds to 90 minutes, preferably from 5 to 60 minutes, is suitably applied according to the nature of the compound of the formula (I) and the treated article.

The plasma chamber used suitably has a volume sufficient to accommodate a plurality of articles.

Particularly suitable apparatus and methods for preparing the articles of the present invention are described in WO2005/089961, the disclosure of which is incorporated herein by reference.

In particular, when using a high volume chamber of this type, a voltage in the form of a pulsed field is used, in the range of 0.001 to 500 w/m ³ (eg 0.001 to 100 w/m ³ and suitable for a functional layer of 0.005 to 0.5) The average power of w/m ³ ) produces plasma.

These conditions are particularly suitable for depositing a uniform coating of good quality in a large chamber, for example where the volume of the plasma zone is greater than 500 cm ³ (eg 0.5 m ³ or greater, such as 0.5 m ³ to 10 m ³ and suitable) It is about 1 m ³ ) in the chamber. The layer formed in this way has good mechanical strength.

The chamber will be sized to accommodate the particular item being processed. For example, a cubic chamber can generally be adapted for a range of applications, but if desired, an elongated or rectangular chamber can be created, or the like can be substantially cylindrical or have any other suitable shape.

The chamber may be a sealable container to allow for a batch process, or it may include an inlet and an outlet for such items (e.g., yarn) to allow it to be used in a continuous process. In particular, in the latter case, as is known, for example, in devices having "whistling leaks", high volume pumps are used to control the pressure conditions required to generate a plasma discharge in the chamber. However, certain items may also be disposed of at or near atmospheric pressure to eliminate the need for "whistling leaks."

The monomer may comprise a compound of formula (I): Wherein R ¹ , R ² and R ³ are independently selected from hydrogen, alkyl, haloalkyl or, optionally, halo-substituted aryl; and R ⁴ is a group XR ⁵ wherein R ⁵ is alkyl or haloalkyl And an X-bond, a -C(O)O(CH ₂ ) _n Y- group (wherein n is an integer from 1 to 10, and a Y-bond or a sulfonylamino group), or a group -(O) _p R ⁶ (O) _q (CH ₂ ) _t - (wherein R ⁶ is an aryl group which is optionally substituted with a halogen group, p is 0 or 1, q is 0 or 1 and t is 0 or an integer of 1 to 10, The constraint is that when q is 1, t is not 0).

The single system used is selected from the monomers of formula (I) above. Suitable are haloalkyl fluoroalkyl groups for R ¹ , R ² , R ³ , R ⁴ and R ⁵ . The alkyl chains may be straight or branched and may comprise cyclic groups.

With respect to R ⁵ , the alkyl chains suitably comprise 2 or more carbon atoms, suitably 2 to 20 carbon atoms and preferably 6 to 12 carbon atoms.

In the case of R ¹ , R ² and R ³ , the alkyl chain is usually preferably 1 to 6 carbon atoms.

R ^{5 is} preferably a haloalkyl group, and more preferably a perhaloalkyl group, specifically a formula C _m F _2m+1 perfluoroalkyl group, wherein m is 1 or more, suitably 1 to 20, and preferably An integer from 4 to 12 (eg 4, 6 or 8).

Suitable alkyl groups for R ¹ , R ² and R ³ have from 1 to 6 carbon atoms.

In one embodiment, at least one of R ¹ , R ² and R ³ is hydrogen. In a particular embodiment, R ¹ , R ² and R ³ are both hydrogen. However, in another embodiment, R ³ is an alkyl group such as methyl or propyl.

When the X group is -C(O)O(CH ₂ ) _n Y-, n is an integer providing a suitable spacer. In particular, n is from 1 to 5, preferably about 2.

In the case of Y, a suitable sulfonamide group includes a group of the formula -N(R ⁷ )SO ₂ ^- wherein R ⁷ is hydrogen or an alkyl group, such as a C _1-4 alkyl group, specifically a Base or ethyl.

In one embodiment, the compound of formula (I) is a compound of formula (II): CH ₂ =CH-R ⁵ (II) wherein R ⁵ is as defined above in formula (I).

In the compound of formula (II), the X bond in formula (I).

However, in a preferred embodiment, the compound of formula (I) is an acrylate of formula (III): CH ₂ =CR ⁷ C(O)O(CH ₂ ) _n R ⁵ (III) wherein n and R ⁵ are as defined above Defined in formula (I), and R ⁷ is hydrogen, C _1-10 alkyl or C _1-10 haloalkyl. In particular, R ⁷ is hydrogen or C _1-6 alkyl (such as methyl). A specific example of a compound of formula (III) is a compound of formula (IV): Wherein R ⁷ is as defined above, and is specifically hydrogen, and x is an integer from 1 to 9 (eg, 4 to 9 and preferably 7). In this case, the compound of the formula (IV) is 1H, 1H, 2H, 2H-heptadecafluorodecyl acrylate.

In one embodiment, the compound of formula (IV) is a compound of formula (V): Wherein R ⁸ is hydrogen or methyl, ethyl or propyl; and n = 1 to 5.

A second aspect of the invention provides a hydrophobic and/or oleophobic substrate comprising a polymeric coating that has been coated by the method.

The substrate can include, for example, a fabric or an article of clothing (including footwear) containing the fabric. In addition, the substrate may include an electronic device, a microfluidic device, Laboratory consumables or photovoltaic modules.

Preferred features of the second aspect of the invention may be as described above for the first aspect.

The words "including" and "comprising" and variations of the words "including, but not limited to," in the context of the description and the scope of the claims are intended to be inclusive, and do not exclude other groups, additives, components, integers or step.

In the description of the specification and the claims, the singular includes the plural. In particular, the description should be understood to cover the plural and singular, when the non-limiting articles are used.

Other features of the invention will become apparent from the following examples. In general, the invention extends to any novel or any novel combination of features disclosed in the description of the invention, including any accompanying claims and drawings. Therefore, features, integers, characteristics, compounds, chemical moieties or groups described in connection with a particular aspect, embodiment or example of the invention are to be construed as being applicable to any other Aspect, embodiment or example.

In addition, any feature disclosed herein may be replaced by another feature for the same or similar purpose, unless otherwise specified.

The invention will now be described, by way of example, with reference to the accompanying drawings.

The apparatus for forming a polymer coating is shown in simplified form in Figure 1. The processing chamber 10 has a processing zone 12 and an access opening 14 contained therein. Equipment for producing plasma in the processing chamber is not shown.

A fluid inlet 16 is provided to allow introduction of monomer into the chamber. Other fluids, such as carrier gases or pretreatment gases, may also be introduced via this fluid inlet.

The processing chamber 10 is connected to the vacuum pump 18 via a gate valve 20. The gate valve 20 can be closed or opened (partial or complete). When open, the gate valve allows exhaust gas to be vented and, when used in combination with the vacuum pump, reduces the pressure within the processing zone.

The device also has a controller 22 that controls the fluid inlet, gate valve, and vacuum pump. The controller can be a microprocessor, a PC or any other suitable device.

Figure 2 shows the sequence of events during the loop. In a first step 24, the gate valve is opened and the vacuum pump partially evacuates the processing chamber. In particular, the pressure within the processing chamber is reduced to the desired low pressure. This low pressure allows for an increase in the residence time of the monomer within the process chamber because it cannot escape from the valve and flow downstream with the exhaust gas. In a second step 26, the gate valve is closed (or at least partially closed) and the fluid inlet is opened, which allows the introduction of monomer into the chamber. The pressure in the chamber is gradually increased, and in particular, this is the result of the evaporation of the monomer introduced into the chamber. In a third step 28, the gate valve is opened to allow exhaust gas to be exhausted. The controller controls the activity of the vacuum pump, gate valve, and fluid inlet during such steps in each cycle. This cycle is repeated to maintain the desired residence time of the monomer. The circulation rate can be selected by the time required to reach a particular pressure or by the duration required to convert the monomer to the polymer. The typical number of cycles used is four. In addition, the use of this cycle allows the deposition rate to move within the chamber to make the coating more uniform. In particular, the deposition is moved from the edge of the chamber to the center to improve the coating.

These cycles may be based on time or based on pressure. Time-based cycle In other words, the controller additionally includes a clock or counter that is used to control the length of each cycle and the timing of events in each cycle.

If a pressure based cycle is used, there is one or more pressure sensors in the processing zone, wherein pressure data is output to the controller. In this case, each step occurs when the pressure in the treatment zone reaches a predetermined value.

Example 1

In a first example, a hearing aid is coated with a monomer of the following formula VI:

The plasma polymerized coating is applied in an inductively coupled glow discharge reactor having a leakage rate greater than 6 x 10 ^-9 mol s ^-1 and a monomer flow rate of 4 mg/min or 3.2 mol s ^-1 . This is connected to a secondary Edwards rotary pump via a liquid nitrogen cooled collector, a thermocouple pressure gauge, and a monomer tube containing the monomer. A 13.56 MHz radio frequency (RF) generator is used to provide discharge power.

A hearing aid with a structured ABS plastic outer surface was placed in the center of the chamber and the chamber was then evacuated to 20 mTorr.

A glow discharge was initiated and the chamber was subjected to a 150 W continuous wave (CW) for 30 s, during which time the monomer was injected twice (3 seconds apart) into the chamber.

Then, while injecting the monomer into the chamber, a 450 W pulse wave (PW) was applied with a load cycle (0.35%) of 35 microseconds on and 10 milliseconds off; operation was performed 140 times, with an interval of 3 seconds between operations. .

During this PW phase, the pressure in the chamber was cycled as follows: once the pressure in the chamber reached 50 mTorr, the gate valve was closed for 60 seconds. After 60 seconds, The gate is opened at a fixed percentage (50% to 100%). When the pressure drops to 50 mTorr, the gate is closed again for 60 seconds and the cycle is repeated. This cycle is repeated for the duration of the PW cycle (i.e., about 420 seconds).

Repeat this method without a pressure cycle. The conditions are identical to the above except that the gate valve is kept open for the duration of the continuous wave phase and the PW phase.

Then, the effect of plasma deposition on the surface energy of the treated substrate was measured. Water was applied to the surface of the treated hearing aid and the contact angle was measured. The tests were performed on the surface of the coated hearing aid and after the coating was subjected to 1,000 abrasions (using the same test as in Example 2). The results of the coatings applied using pressure cycling and without pressure cycling are summarized in the table below.

It can be seen from Table 1 that a larger contact angle is achieved using a pressure cycle (both initially and after abrasion). This shows that using a pressure cycle achieves the desired level of performance of the coating faster than without using a pressure cycle.

Example 2

In a second example, a mobile phone comprising different substrates of plastic, glass and metal is applied. The same apparatus and monomers as described in Example 1 were used.

The chamber was evacuated to 20 mTorr, then a glow discharge was initiated and the chamber was subjected to a 150 W continuous wave (CW) for 30 s, during which time the monomer was split into two Injections (3 seconds apart) were injected into the chamber.

Then, while injecting the monomer into the chamber, a 300 W pulse wave (PW) was applied in a load cycle (0.35%) of 35 microseconds on and 10 milliseconds off; operation was performed 140 times, with an interval of 3 seconds between operations. .

During this PW phase, the pressure in the chamber was cycled as follows: once the pressure in the chamber reached 50 mTorr, the gate valve was closed for 60 seconds. After 60 seconds, the gate is opened at a fixed percentage (50% to 100%). When the pressure drops to 50 mTorr, the gate is closed again for 60 seconds and the cycle is repeated. This cycle is repeated for the duration of the PW cycle (i.e., about 420 seconds).

Repeat this method without a pressure cycle.

Then, the effect of plasma deposition on the surface energy of the treated substrate was measured. Water was applied to the surface of the treated hearing aid and the contact angle was measured. These coatings were applied to the surface of the coated hearing aid and after a thousand abrasions of the coating using a Taber 5750 linear abrasion tester with standard Martinate abrasion fabric (500 g weight and 1 inch wear path). test. The results of the coatings applied using pressure cycling and without pressure cycling are summarized in the table below.

As in the previous examples, the use of a pressure cycle coated coating produced greater contact angle. This contact angle changes little after abrasion. As noted above, this is believed to be due to the faster formation of the coating.

Example 3

In a third example, a mobile phone comprising different substrates of plastic, glass and metal is applied. The same apparatus and monomers as described in Example 1 were used.

The chamber was evacuated to 20 mTorr, then a glow discharge was initiated and the chamber was subjected to a 150 W continuous wave (CW) for 30 s during which time the monomer was injected once into the chamber.

Then, while injecting the monomer into the chamber, a 450 W pulse wave (PW) was applied with a load cycle (0.35%) of 35 microseconds on and 10 milliseconds off; 130 operations were performed, with an interval of 3 seconds between operations. .

During the PW phase, the pressure in the chamber is circulated by alternately opening and closing the gate valve for a period of 60 seconds.

This method is repeated without a pressure cycle during which the gate remains open for the duration of the CW and PW phases.

Then, the effect of the plasma deposition on the surface energy of the treated substrate was measured using the same method as described in Example 2.

Table 3 shows that the deposition on the inside of the phone is greatly increased when pressure cycling is used compared to the case without circulation.

As shown in these examples, use variable pressure cycles to accelerate the desired performance The standard method is to speed up processing time.

As shown in Example 3, improvements were observed not only on the exterior of the product, but also on the interior of the complex product. Using the acyclic method to achieve the same result will require longer processing times and more monomer (although it may still not reach the same level of performance).

By speeding up the processing time, the pressure cycle also has the effect of using fewer monomers. Other advantages include improved coating uniformity. In addition, the required level of performance occurs throughout the processing chamber.

The increase in residence time has other advantages, such as increasing the permeability of such coatings into, for example, corners and gaps in electronic devices. In addition, an increase in residence time allows the formation of a coating from monomers that are not well polymerized under conventional conditions, such as short chain monomers such as 1H, 1H, 2H, 2H-tridecafluorooctyl acrylate.

10‧‧‧Processing room

12‧‧‧Processing area

14‧‧‧Getting started

16‧‧‧ fluid inlet

18‧‧‧ vacuum pump

20‧‧‧ gate valve

22‧‧‧ Controller

24‧‧‧First steps

26‧‧‧ second step

28‧‧‧ third step

Figure 1 shows a device for practicing the invention; and Figure 2 is a flow chart showing events in various variable pressure cycles.

24‧‧‧First steps

26‧‧‧ second step

28‧‧‧ third step

Claims (25)

A method of forming a liquid repellent coating on a surface of a substrate, the method comprising: exposing the surface to the monomer to form a polymer layer in a plasma deposition process while maintaining the monomer in situ for a period of time On the surface, wherein the conditions comprise at least one cycle of varying pressure. The method of claim 1 wherein the substrate is exposed to the plasma in the processing chamber and the processing chamber is at least partially evacuated at the beginning of each cycle. The method of claim 1 or claim 2, wherein each cycle comprises continuously introducing the monomer into the processing chamber and allowing the pressure to rise. The method of claim 2 or claim 3, wherein the exhaust gas is discharged from the processing chamber at the end of each cycle. The method of any of the preceding claims, wherein a valve is used to control the pressure inside and outside the process, wherein the valve is used to increase the residence time of the monomer in the chamber to allow formation of a polymer layer. The method of any of the preceding claims, wherein the maximum pressure is equal to or lower than 150 mTorr, and more specifically equal to or lower than 125 mTorr. The method of any of the preceding claims, wherein the at least one cycle of the varying pressures comprises a time based cycle and/or a pressure based cycle. The method of any of the preceding claims, wherein each cycle is between 45 and 75 seconds. The method of any of the preceding claims, wherein exposing the surface to at least one cycle of varying pressure comprises exposing the surface to two or more cycles of varying pressure, and in particular, the two or more Multiple cycles include 5 to 12 cycles, and more specifically 8 or 9 cycles. The method of any of the preceding claims, wherein the single system (I) compound: Wherein R ¹ , R ² and R ³ are independently selected from hydrogen, alkyl, haloalkyl or, optionally, halo-substituted aryl; and R ⁴ is a group XR ⁵ wherein R ⁵ is alkyl or haloalkyl And an X-bond, a -C(O)O(CH ₂ ) _n Y- group (wherein n is an integer from 1 to 10, and a Y-bond or a sulfonylamino group), or a group -(O) _p R ⁶ (O) _q (CH ₂ ) _t - (wherein R ⁶ is an aryl group which is optionally substituted with a halogen group, p is 0 or 1, q is 0 or 1 and t is 0 or an integer of 1 to 10, The constraint is that when q is 1, t is not 0). The method of claim 10, wherein the compound of formula (I) is a compound of formula (II): CH ₂ =CH-R ⁵ (II) wherein R ⁵ is as defined in claim 10; or a compound of formula (III): CH ₂ =CR ⁷ C(O)O(CH ₂ ) _n R ⁵ (III) wherein n and R ⁵ are as defined in claim 10, and R ⁷ is hydrogen, C _1-10 alkyl or C _{1- 10} haloalkyl. The method of claim 11, wherein the compound of formula (I) is a compound of formula (III). The method of claim 12, wherein the compound of formula (III) is a compound of formula (IV): Wherein R ⁷ is as defined in claim 11 and x is an integer from 1 to 9. The method of claim 13, wherein the compound of the formula (IV) is 1H, 1H, 2H, 2H-heptadecafluorodecyl acrylate. The method of claim 13, wherein the compound of formula (IV) is a compound of formula (V): Wherein R ⁸ is hydrogen or methyl, ethyl or propyl, and n = 1 to 5. The method of any of the preceding claims, wherein the plasma deposition method is a plasma polymerization method, and the coating is applied using a pulsed plasma. The method of claim 16, wherein the pulse sequence comprises an on ratio of 1:200 to 1:1500. The method of any one of claims 16 or 17, wherein the pulse sequence comprises energizing 20 to 50 μs and powering down 500 μs to 30,000 μs. The method of any of the preceding claims, wherein the average power level is from 1 W to 1 kW, and more specifically from 300 W to 500 W. The method of any of the preceding claims, wherein in the initial step, continuous power plasma is applied to the surface. The method of claim 20, wherein the initial step is carried out in the presence of an inert gas. The method of any of the preceding claims, wherein the liquid repels the coating package Includes oil or water resistant coating. The method of any of the preceding claims, wherein the surface is a surface of a fabric, metal, glass, ceramic, paper or polymer substrate. A liquid repellent substrate comprising a polymeric coating that has been coated by the method of any of the preceding claims. The substrate of claim 24, which comprises a fabric, and in particular an article of clothing.