TW202016349A - An antistatic liquid proof nano coating and preparation method thereof - Google Patents

Abstract

The invention provides an antistatic liquid proof nano coating and a preparation method thereof, which are characterized in that a substrate is exposed to a monomer vapor atmosphere, and a chemically reacting on the surface of the substrate by plasma discharge to form a protective coating. The monomer vapor is a mixture of monomer 1 having a specific structure and monomer 2 having a conjugated structure. The coating prepared by the method of the present application increases the contact angle of the surface of the substrate, improves the hydrophobicity of the surface of the coating, and at the same time, obtains good antistatic properties.

Description

Anti-static liquid-repellent nano coating and preparation method thereof

The invention relates to the technical field of plasma chemical vapor deposition, in particular to an antistatic and liquid-repellent nano-coating and a preparation method thereof.

The generation and accumulation of static electricity bring a lot of trouble to people's daily life and industrial production, and even cause major safety accidents such as fires and explosions.

On the surface of high-precision components such as electronic products, once static electricity accumulates to a certain extent, it is easily affected by the discharge of static electricity, which is prone to short-circuits, resistance drift, and degradation of working performance. Fluoropolymers have significant advantages such as hydrophobicity, thermal stability, chemical resistance, and oxidation resistance, and are often used as the main component of protective coatings in electrical equipment, transportation equipment, semiconductors, and other fields. However, the surface conductivity of this type of polymer is very poor, and the accumulation of static electricity on the surface of electronic devices is prone to occur.

In order to improve the conductive properties of the coating, the conventional method is to add some good conductive materials into the coating, such as carbon nanotubes, graphene, metal oxides, etc. For example, CN107880729 A "Antistatic Coating and Coating Process" discloses an antistatic coating, which includes a graphene substrate sealing layer, a conductive ground layer, a graphene intermediate layer, and a graphene antistatic topcoat. The electrostatic function mainly comes from conductive graphene, which is compounded as an additive in the coating. However, in this method, the conductive material is unevenly dispersed, and it is prone to agglomeration, resulting in an ineffective antistatic ability. Compared with this, there are some organic substances with conjugated structure, under certain chemical reaction conditions, they can obtain conductive polymers by their own polymerization. However, there are few reports on the application of this conductive polymer to the nano-film coating to improve its antistatic performance.

At present, the synthesis of conductive polymers is mainly induced by special chemical catalysts. The resulting polymer is difficult to process after molding, and it is difficult to compound with other polymers. When it is compounded with a fluorocarbon nanofilm coating with hydrophobic and oleophobic properties to improve antistatic performance, it is even more difficult to achieve using conventional means.

In order to overcome the above shortcomings, the present invention provides an antistatic and liquid-repellent nano-coating and a preparation method thereof. Under the plasma conditions, through the selection of monomers and the regulation of plasma energy, conductive polymer monomers are deposited together in the coating during the deposition of the fluorocarbon coating, which improves the antistatic ability of the coating and can achieve The hydrophobic and liquid-repellent effect of the coating.

The present invention is achieved through the following technical solutions:

An anti-static and liquid-repellent nano-coating, which exposes the substrate to the atmosphere of monomer steam, and forms a protective coating by plasma discharge on the surface of the substrate through chemical reaction;

The monomer vapor includes: monomer 1 and monomer 2;

The monomer 1 has a structure represented by formula (I) or formula (II);

The monomer 2 has a conjugated structure;

單體1結構式如下：

The structural formula of monomer 1 is as follows:

(I)

或，                                        (II)；

Or, (II);

Wherein, R ¹ , R ² , R ³ and R ⁵ are groups connected to unsaturated bonds and are independently selected from hydrogen, alkyl, aryl, halogen, haloalkyl or haloaryl;

R ⁴ and R ⁶ are fluorine-containing hydrophobic groups selected from F or groups having the following structure:

-C _x H _y F _2x+1-y , -COO-C _x H _y F _2x+1-y or -COO-C _x H _y (OH) _z F _2x+1-yz ;

x is an integer from 1-20, y is an integer from 0-41, and z is an integer from 0-20.

Monomer 2 with a conjugated structure, including structures with π-π conjugation, large π bond conjugation, p-π conjugation, σ-π conjugation, etc. The conjugated structure can change the migration of electrons along the main chain It is easy to make the polymer gain conductivity. Monomer 2 can be selected from acetylene derivatives, cyclooctatetraene derivatives, pyrrole derivatives, thiophene derivatives, aniline derivatives, benzene, phenyl sulfide or quinoline, etc. After research, it is found that the above substances can be selected from monomers 1 working together to make the coating of the present invention have antistatic properties while not damaging the hydrophobic and liquid-repellent properties of the coating.

Preferably, R ¹ , R ² , R ³ and R ⁵ are hydrogen, methyl or fluorine.

The proper carbon chain length can make the monomer liquid at normal temperature and pressure, and under certain vacuum conditions, the monomer can be easily vaporized into the reaction chamber for deposition reaction. Preferably, X is an integer of 2-15 , Y is an integer of 0-20, z is an integer of 0-2.

In addition, the invention also discloses a method for preparing the above nano-coating, which includes the following steps:

(1) Place the substrate in the reaction chamber of the plasma chamber, the vacuum in the reaction chamber is 0.1 mTorr-100 Torr;

(2) Inject the plasma source gas, start the plasma discharge for deposition, and introduce the monomer vapor into the reaction chamber to carry out the chemical vapor deposition reaction;

(3) Turn off the plasma discharge for deposition, pass clean compressed air or inert gas, the chamber returns to normal pressure, open the reaction chamber, and take out the substrate.

Preferably, the plasma source gas is helium, and the flow rate when the plasma source gas passes into the reaction chamber is 1-500 sccm.

Monomer 1 and monomer 2 may be introduced simultaneously, or monomer 1 may be introduced first and then monomer 2 may be introduced. Among them, the molar ratio of monomer 2 to the total monomer vapor does not exceed 50%.

Preferably, the temperature of the reaction chamber of the plasma chamber is controlled at 30-60°C. Step (2) The vaporization temperature of the monomer 1 and/or the monomer 2 is 60°C-150°C, and the vaporization is performed under reduced pressure.

Specifically, the monomer 1 and/or the monomer 2 are vaporized under a vacuum of 0.1 mtorr to 100 torr.

Preferably, in the step (2), after passing the plasma source gas and before the plasma discharge for deposition, a plasma discharge step for pretreatment of the substrate is further included.

Preferably, the plasma discharge (plasma discharge for deposition and/or plasma discharge for pretreatment) is radio frequency discharge, microwave discharge, intermediate frequency discharge, Penning discharge or electric spark discharge.

Preferably, the plasma discharge (plasma discharge for deposition and/or plasma discharge for pretreatment) is a microwave discharge with a frequency of 500 MHz-300 KMHz. The plasma discharge time is 10s-14400s.

Compared with the prior art, in the preparation method of the antistatic polymer coating in the present invention:

(1) No special chemical catalyst is required to induce polymerization, but plasma activation polymerization is adopted to reduce the cost of the catalyst; (2) The conductive polymer of the present invention is directly deposited on the surface of the substrate without further processing and blending, which reduces the cost .

(3) In the present invention, the plasma vapor deposition method is used to prepare the nano-coating, and the conductive polymer additive is uniformly mixed with the coating, which is favorable for forming a conductive network and improving the anti-static effect of the coating.

(4) The coating prepared by the monomer and preparation method determined in this application can not only prevent static electricity, but also have good hydrophobic and liquid-repellent properties. The problem that the addition of conventional antistatic additives can damage the hydrophobic and liquid-repellent properties of the nano-coating is avoided.

Examples 1

In the preparation method of the antistatic polymer coating in the present invention, the following steps are performed:

(1) Place a 10cm×10cm polytetrafluoroethylene block in a 100L plasma vacuum reaction chamber, and evacuate the reaction chamber continuously to achieve a vacuum of 1 mTorr.

(2) Introduce helium gas with a flow rate of 50 sccm. Turn on the RF plasma discharge to pretreat the PTFE block base material (that is, turn on the RF mode pretreatment plasma discharge). The discharge power in this pretreatment stage is 20W, continuous discharge for 300s.

(3) The monomer 1a is introduced first, and after the end, the monomer 2a is introduced to perform chemical vapor deposition on the surface of the substrate to prepare a nano-coating. The flow rate of the two monomers in the coating preparation process is 50 μL/min, and the introduction time is 1600 s and 400 s, respectively. The plasma discharge for pretreatment is adjusted to the plasma discharge for deposition. The plasma discharge in this deposition stage uses a microwave discharge method to generate plasma, with a microwave discharge frequency of 500 MHz and a discharge power of 30 W.

(4) After the coating preparation is completed, nitrogen gas is introduced to restore the reaction chamber to normal pressure, the chamber is opened, and the Teflon block is removed. Monomer 2a is aniline.

Monomer 1a

Monomer 2a

Among them, the device for plasma discharge for pretreatment and the device for plasma discharge for deposition may be one set or two separate devices. The plasma discharge device (for example, electrode) for pretreatment is preferably arranged in the reaction chamber and around the base material, so as to facilitate the quick connection with the coating process after pretreatment; the plasma discharge device for deposition can be arranged in the reaction chamber It is installed outside and away from the reaction chamber, so as to avoid the negative influence of the plasma discharge on the substrate during the coating process selectively or as far as possible.

Examples 2

In the preparation method of the antistatic polymer coating in the present invention, the following steps are performed:

(1) Place a 10cm×10cm metal zinc sheet in a 1000L plasma vacuum reaction chamber, and continuously evacuate the reaction chamber to achieve a vacuum of 10 mtorr.

(2) Introduce helium gas with a flow rate of 20 sccm. Turn on the microwave plasma discharge to pretreat the metal zinc sheet substrate (that is, turn on the microwave-type pretreatment plasma discharge). The discharge power in this pretreatment stage is 80W for continuous Discharge for 300s.

(3) The monomer 1b is introduced first, and then the monomer 2b is introduced later, and chemical vapor deposition is performed on the surface of the substrate to prepare a nano-coating. During the preparation of the coating, the flow rate of the two monomers was 100 μL/min, and the introduction time was 2000 s and 100 s, respectively. The plasma discharge for pretreatment was adjusted to a plasma discharge for deposition. The microwave discharge frequency at this deposition stage was 1 GHz, and the discharge power was 100 W.

(4) After the coating preparation is completed, nitrogen gas is introduced to restore the reaction chamber to normal pressure, the chamber is opened, and the Teflon block is removed. Monomer 2b is cyclooctatetraene.

Monomer 1b

Monomer 2b

Examples 3

In the preparation method of the antistatic polymer coating in the present invention, the following steps are performed:

(1) Place 10cm×10cm glass in the 500L plasma vacuum reaction chamber, and continuously evacuate the reaction chamber to achieve a vacuum of 100 mTorr.

(2) Introduce helium gas with a flow rate of 90sccm. Turn on the microwave plasma discharge to pretreat the glass substrate (that is, turn on the microwave type pretreatment plasma discharge). The discharge power in this pretreatment stage is 120W, and the discharge continues for 100s. .

(3) Simultaneously introduce monomers 1c and 2c, and perform chemical vapor deposition on the surface of the substrate to prepare a nano-coating. The flow rate of the two monomers in the coating preparation process was 200 μL/min and 10 μL/min, respectively, and the passing time was 3000 s. The plasma discharge for pretreatment was adjusted to a plasma discharge for deposition. In this deposition stage, the microwave discharge frequency was 2.45 GHz, and the discharge power was 400 W.

(4) After the coating preparation is completed, nitrogen gas is introduced to restore the reaction chamber to normal pressure, the chamber is opened, and the Teflon block is removed. Monomer 2c is quinoline.

Monomer 1c

Monomer 2c

Examples 4

Compared with Example 1, the monomers 1a and 2a in step (3) were replaced with 1d and 2d, respectively, the monomer 1d passing time was 1500s, and the monomer 2d passing time was 3000s.

Monomer 1d

Monolithic 2d

Examples 5

Compared with Example 1, in step (3), monomers 1a and 2a are replaced with 1e and 2e, respectively, the monomer 1e introduction time is 2000s, and the monomer 2e introduction time is 3500s.

Monomer 1e

Monomer 2e

Examples 6

Compared with Example 1, the discharge power in step (3) was changed to 300 W, and other conditions were not changed.

Examples 7

Compared with Example 2, the vacuum degree in step (1) was changed to reach 50 mTorr, and other conditions were not changed.

Examples 8

Compared with Example 3, the flow rates of the two monomers 1c and 2c in step (3) were changed to 500 μL/min and 50 μL/min, respectively, and other conditions were not changed.

Examples 9

Compared with Example 3, the monomer passing time in step (3) was changed to 5000 s, and other conditions were not changed.

Comparative example 1

Compared with Example 2, step (3) does not introduce monomer 2b, the monomer flow rate of 1b is changed to 200 μL/min, and other conditions are not changed.

Comparative example 2

Compared with Example 3, in step (3), monomer 2c is not introduced, and the flow rate of monomer 1c is changed to 210 μL/min, and other conditions are not changed.

The thickness of the coating, the water contact angle, and the surface resistance of the substrate after the plating in the above embodiments were measured.

The thickness of the nano-coating is tested using the US Filmetrics F20-UV-thickness film thickness measuring instrument.

Nano-coating water contact angle, tested according to GB/T 30447-2013 standard. The test method of surface resistance is tested according to GB/T 1410-2006 standard.

Table 1

It can be seen from Table 1 that the nanocoating prepared by the present invention has good antistatic performance, and can be optimized by changing the process conditions in terms of the thickness of the nanocoating and the water contact angle of the nanocoating.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention, rather than limiting it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: The technical solutions described in the foregoing embodiments can still be modified, or some or all of the technical features can be equivalently replaced; and these modifications or replacements do not deviate from the essence of the corresponding technical solutions of the technical solutions of the embodiments of the present invention. range.

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Claims (11)

An anti-static and liquid-repellent nano-coating, characterized in that the substrate is exposed to a monomer vapor atmosphere, and a chemical reaction occurs on the surface of the substrate by plasma discharge to form a protective coating; the monomer vapor includes: monomer 1 And monomer 2; the monomer 1 has a structure represented by formula (I) or formula (II); the monomer 2 has a conjugated structure; the monomer 1 has the structural formula as follows:

(I)

Or, (II); wherein, R ¹ , R ² , R ³ , and R ^{5 are} independently selected from hydrogen, alkyl, aryl, halogen, or haloalkyl, and R ⁴ and R ^{6 are} selected from F or a group having the following structure Group: -C _x H _y F _2x+1-y , -COO-C _x H _y F _2x+1-y or -COO-C _x H _y (OH) _z F _2x+1-yz ; x is 1- Integer of 20, y is an integer of 0-41, z is an integer of 0-20; monomer 2 having a conjugated structure is an acetylene derivative, cyclooctatetraene derivative, pyrrole derivative, thiophene derivative, aniline derivative Benzene, benzene sulfide or quinoline. The anti-static and liquid-repellent nano-coating according to item 1 of the patent application range, wherein R ¹ , R ² , R ³ and R ⁵ are hydrogen, methyl or fluorine. The antistatic and liquid-repellent nanocoating according to item 1 of the patent application range, wherein x is an integer of 2-15, y is an integer of 0-20, and z is an integer of 0-2. A method for preparing an anti-static and liquid-repellent nano-coating according to any one of the first to third patent applications, characterized in that it includes the following steps: (1) Place the substrate in the reaction chamber of the plasma chamber, and the vacuum in the reaction chamber is from 1 mtorr to 100 torr; (2) Inject the plasma source gas, start the plasma discharge for deposition, and introduce the monomer vapor into the reaction chamber to carry out the chemical vapor deposition reaction; (3) Turn off the plasma discharge for deposition, pass clean compressed air or inert gas, the chamber returns to normal pressure, open the reaction chamber, and take out the substrate. The preparation method according to item 4 of the patent application range, wherein the plasma source gas is helium, and the flow rate of the plasma source gas when it is introduced into the reaction chamber is 1-500 sccm. The preparation method according to item 4 of the patent application scope, wherein the monomer vapor includes monomer 1 and monomer 2; The monomer 1 and the monomer 2 are simultaneously led into the reaction chamber; Alternatively, the monomer 1 and the monomer 2 respectively pass into the reaction chamber successively. The preparation method according to item 6 of the patent application range, wherein the molar ratio of the monomer 2 to the monomer vapor does not exceed 50%. The preparation method according to item 4 of the patent application range, wherein the temperature of the reaction chamber of the plasma chamber is controlled at 30-60°C. The preparation method according to item 4 of the patent application range, characterized in that, in step (2), the vaporization temperature of the monomer 1 and/or the monomer 2 is 60° C.-150° C., and the vaporization is under reduced pressure ; The monomer 1 and/or the monomer 2 are vaporized under a vacuum of 0.1 mtorr to 100 torr. According to the preparation method described in item 4 of the patent application scope, the plasma discharge method is radio frequency discharge, microwave discharge, intermediate frequency discharge, penning discharge or electric spark discharge. The preparation method according to item 4 or item 10 of the patent application range, wherein the plasma discharge method is microwave discharge with a frequency of 500MHz-300KMHz; and the plasma discharge time is 10s-14400s.