CN114855142B - A kind of parylene material with low surface energy and preparation method thereof - Google Patents

Abstract

The invention provides a low-surface-energy parylene material and a preparation method thereof, which are based on the existing parylene material, the surface energy of the parylene material is reduced while the original excellent physical and chemical properties of the parylene material are maintained, and the surface of the parylene material after coating can reach a super-hydrophobic state by combining a substrate with a micro-nano structure, so that the self-cleaning property under certain specific working conditions is realized. The low surface energy parylene material is formed by chemical vapor deposition of a parylene raw material and a fluorine-containing reagent. The preparation method comprises the following steps: step 1, placing a parylene raw material and a fluorine-containing reagent into an evaporation chamber; step 2, vacuumizing the whole reaction device to ensure that the reaction occurs under the vacuum condition; step 3, firstly raising the temperature of the cracking furnace to 690 ℃ or 650 ℃, and then raising the temperature of the evaporating chamber to 175 ℃; and 4, depositing a film on the substrate in the room temperature chamber after the raw materials react.

Description

A kind of parylene material with low surface energy and preparation method thereof

technical field

The invention relates to the technical field of functional material surfaces, in particular to a parylene material with low surface energy and a preparation method thereof.

Background technique

Parylene is a new type of conformal coating material developed and applied by Union Carbide Co. in the United States in the mid-1960s. It is a polymer of p-xylene. According to different molecular structures, Parylene can be divided into N type, C type, D type, F type, HT type and other types. Parylene is a protective polymer material. Its Chinese name is parylene. Parylene can be vapor-deposited under vacuum. The good penetrating power of the active molecules of Parylene can form a pinhole-free transparent insulating coating with uniform thickness on the inside, bottom and surrounding of electronic components, providing a complete high-quality protective coating for components to resist acid, alkali, salt spray, mold and various corrosive gases.

However, the existing parylene materials have high surface energy and have shortcomings such as limited application scenarios.

Contents of the invention

The invention provides a parylene material with low surface energy and a preparation method thereof. Based on the existing parylene material, while maintaining its original excellent physical and chemical properties, its surface energy is reduced, combined with a substrate with a micro-nano structure, so that the surface of the coated film reaches a super-hydrophobic state, and realizes the self-cleaning characteristic under certain specific working conditions.

The technical problem to be solved by the present invention is achieved through the following technical solutions:

The invention provides a parylene material with low surface energy, which is formed by chemical vapor deposition of parylene raw materials and fluorine-containing reagents.

Preferably, the fluorine-containing reagents include 2,2,3,3,4,4,5,5,6,6,7,7-dodecafluoro-1,8-octanediol, 3,3,3-trifluoroethyl propionate, nine-carbon perfluoropolyether siloxane, 2,2,2-trifluoroethyl trifluoroethyl ester, perfluoropolyether, 2,2,2-trifluoroacetamide, perfluorononane, perfluorodecyl ethyl acrylate, undecafluoron-hexane-1-ol, Perfluorodecane.

Preferably, the difference between the evaporation temperature of the parylene raw material and the evaporation temperature of the fluorine-containing reagent is less than or equal to 25°C.

Preferably, the difference between the evaporation temperature of the parylene raw material and the evaporation temperature of the fluorine-containing reagent is 0°C to 25°C.

Preferably, the cracking temperature of the fluorine-containing reagent is lower than 700°C.

A kind of preparation method of the parylene material of low surface energy, comprises the following steps:

Step 1. Put the parylene raw material and fluorine-containing reagent into the evaporation chamber;

Step 2, vacuumize the whole reaction device to ensure that the reaction takes place under vacuum conditions;

Step 3, first raise the temperature of the cracking furnace to 690°C or 650°C, and then raise the temperature of the evaporation chamber to 175°C;

Step 4, after the reaction of the raw materials, deposit and form a film on the substrate in the chamber at room temperature.

Preferably, in step 1, if the difference between the evaporation temperatures of the parylene raw material and the fluorine-containing reagent is >10°C, then the parylene raw material and the fluorine-containing reagent should be placed separately into the evaporation chamber; if the difference between the evaporation temperatures of the parylene raw material and the fluorine-containing reagent is <10°C, the parylene raw material and the fluorine-containing reagent can be mixed and put into the evaporation chamber.

Preferably, the base material can be any material.

Preferably, if the base material is a metal substrate, it needs to be treated to enhance the adhesion performance.

Preferably, the raw material that cannot be deposited in step 4 passes through the cold well and adheres to the low-temperature cold well rod to prevent it from entering the vacuum pump.

The beneficial effects of the present invention are:

1. The parylene material with low surface energy of the present invention has higher contact angle and excellent physical and chemical properties, such as higher dielectric constant and better mechanical properties;

2. The parylene material with low surface energy of the present invention has persistence and stable performance based on its bulk properties;

3. The low surface energy parylene material of the present invention has a variety of adjustable factors, which can be flexibly adapted to the needs of different application scenarios;

4. The low surface energy parylene material of the present invention has a simple preparation method, a wide range of raw materials to choose from, and low cost, which is conducive to large-scale production.

Description of drawings

Fig. 1 is the schematic diagram of the preparation method of parylene material of low surface energy of the present invention;

Fig. 2 is that the parylene material section of the low surface energy of the embodiment of the present invention 5 is a porous structure;

Fig. 3 is the parylene material sample contact angle test result of low surface energy of the present invention;

Fig. 4 is the experimental result of the mechanical property test of the parylene material sample with low surface energy of the present invention.

Detailed ways

In order to make the object, technical solution and advantages of the present invention more clear, the present invention will be further described in detail below in conjunction with the examples. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

Fig. 1 is a schematic diagram of the preparation method of the low surface energy parylene material of the present invention. The low surface energy parylene material of the present invention can be prepared by the following method, and the specific method can be adjusted according to factors such as different parylene materials and different fluorine-containing reagents. Taking parylene C as the basic material as an example, the specific method is given below. The process of preparing with other basic materials can be referred to.

Preparation method: CVD chemical vapor deposition

Step 1: Put the parylene C raw material and the fluorine-containing reagent into the evaporation chamber together;

Step 2: Vacuumize the entire reaction device to ensure that the reaction takes place under vacuum conditions;

Step 3: first raise the temperature of the cracking furnace to 690°C, and then raise the temperature of the evaporation chamber to 175°C.

Step 4: Deposit and form a film in a chamber at room temperature after the raw materials are reacted.

Embodiments of the present disclosure will be described in detail below in conjunction with examples, but those skilled in the art will understand that the following examples are only for illustrating the present disclosure, and should not be regarded as limiting the scope of the present disclosure. The parylene used in the following examples is Dichloro-p-cyclophane and Di-p-xylene[2,2]paracyclophane produced in the United States. Those who do not indicate the specific conditions in the examples are carried out according to the conventional conditions or the conditions suggested by the manufacturer. The reagents or instruments used were not indicated by the manufacturer, and they were all commercially available conventional products.

Example 1

Take out the parylene C raw material from the vacuum drying tank, weigh the required weight and put it into the evaporation chamber. After the cracking chamber is heated to 690°C, the evaporation chamber is heated to 175°C. After evaporation, the parylene C raw material undergoes a chemical reaction in the cracking chamber, and then deposits on the substrate in a chamber at room temperature to form a film. The undeposited raw material passes through the cold well and adheres to the low-temperature cold well rod to prevent it from entering the vacuum pump. The base material is a general glass sheet.

Example 2

Take out the parylene N raw material from the vacuum drying tank, weigh the required weight and put it into the evaporation chamber. After the cracking chamber is heated to 650°C, the evaporation chamber is heated to 175°C. The parylene N raw material reacts chemically in the cracking chamber after being evaporated, and then deposits on the substrate in a chamber at room temperature to form a film. The undeposited raw material passes through the cold well and adheres to the low-temperature cold well rod to prevent it from entering the vacuum pump. The base material is a general glass sheet.

Example 3

Take out the parylene C raw material from the vacuum drying tank, weigh the required weight; weigh perfluorononane according to a certain mass-to-volume ratio. If the difference in evaporation temperature of the two raw materials is less than 10°C, they can be mixed and placed in the evaporation chamber; if the difference in evaporation temperature of the two raw materials is greater than 10°C, they need to be placed in the evaporation chamber separately. After the cracking chamber is heated to 690°C, the evaporation chamber is heated to 175°C. Parylene C and the fluorine-containing reagent undergo a chemical reaction in the cracking chamber after evaporation, and then deposit on the substrate in a chamber at room temperature to form a film. The undeposited raw material passes through the cold well and adheres to the low-temperature cold well rod to prevent it from entering the vacuum pump. The base material is a general glass sheet.

Example 4

Take out the parylene N raw material from the vacuum drying tank, and weigh the required weight; weigh perfluorononane according to a certain mass-to-volume ratio. If the difference in evaporation temperature of the two raw materials is less than 10°C, they can be mixed and placed in the evaporation chamber; if the difference in evaporation temperature of the two raw materials is greater than 10°C, they need to be placed in the evaporation chamber separately. After the cracking chamber is heated to 650°C, the evaporation chamber is heated to 175°C. Parylene N and the fluorine-containing reagent undergo a chemical reaction in the cracking chamber after evaporation, and then deposit on the substrate in a chamber at room temperature to form a film. The undeposited raw material passes through the cold well and adheres to the low-temperature cold well rod to prevent it from entering the vacuum pump. The base material is a general glass sheet.

Example 5

Take out the parylene C raw material from the vacuum drying tank, weigh the required weight; weigh perfluorononane according to a certain mass-to-volume ratio. If the difference in evaporation temperature of the two raw materials is less than 10°C, they can be mixed and placed in the evaporation chamber; if the difference in evaporation temperature of the two raw materials is greater than 10°C, they need to be placed in the evaporation chamber separately. After the cracking chamber is heated to 690°C, the evaporation chamber is heated to 175°C. Parylene C and the fluorine-containing reagent undergo a chemical reaction in the cracking chamber after evaporation, and then deposit on the substrate in a chamber at room temperature to form a film. The undeposited raw material passes through the cold well and adheres to the low-temperature cold well rod to prevent it from entering the vacuum pump. The substrate is silicon wafer/PDMS with nanostructures.

Example 6

Take out the parylene N raw material from the vacuum drying tank, and weigh the required weight; weigh perfluorononane according to a certain mass-to-volume ratio. If the difference in evaporation temperature of the two raw materials is less than 10°C, they can be mixed and placed in the evaporation chamber; if the difference in evaporation temperature of the two raw materials is greater than 10°C, they need to be placed in the evaporation chamber separately. After the cracking chamber is heated to 650°C, the evaporation chamber is heated to 175°C. Parylene N and the fluorine-containing reagent undergo a chemical reaction in the cracking chamber after evaporation, and then deposit on the substrate in a chamber at room temperature to form a film. The undeposited raw material passes through the cold well and adheres to the low-temperature cold well rod to prevent it from entering the vacuum pump. The substrate is silicon wafer/PDMS with nanostructures.

Fig. 2 is a cross section of the low surface energy parylene material of Example 5 of the present invention with a porous structure. The parylene material with low surface energy provided by the invention is flat and dense, and has a porous structure in cross section. While maintaining the excellent physical and chemical properties of the original parylene material, the surface energy is reduced, and the contact angle is greatly increased.

Fig. 3 is the experimental result of the contact angle test of the low surface energy parylene material sample of the present invention. The samples prepared in Examples 1-6 were taken, numbered as samples S1-S6 in sequence, and subjected to the contact angle test.

Comparing the experimental data of contact angle of 6 groups of samples:

Sample S1: unstructured parylene C film (the sample prepared in Example 1) before modification;

Sample S2: unstructured parylene N thin film (the sample prepared in Example 2) before modification;

Sample S3: Parylene C thin film (the sample prepared in embodiment 3) after modification without structure;

Sample S4: Parylene N thin film (sample prepared in Example 4) after modification without structure;

Sample S5: the modified Parylene C film (the sample prepared in Example 5) covered on the nanostructure;

Sample S6: the modified Parylene N film (the sample prepared in Example 6) covered on the nanostructure;

Get the samples prepared in Examples 1-4, numbered as samples S1-S4 in sequence, and test their dielectric constant and mechanical properties. The statistical data are shown in Table 1 and Fig. 4 below:

Table 1 Sample S1-S4 Dielectric Constant Experimental Results

It can be seen that compared with the original parylene raw material, the modified parylene material not only has lower surface energy, but also has a lower dielectric constant and improved mechanical properties.

While features of the present invention have been shown and described in detail with reference to a preferred embodiment, it will be understood by those skilled in the art that other changes may be made therein without departing from the spirit and scope of the invention. Likewise, the various diagrams may depict exemplary architectures or other configurations for the present disclosure, which are used to understand the features and functions that may be included in the present disclosure. The present disclosure is not limited to the illustrated example architectures or configurations, but can be implemented using various alternative architectures and configurations. In addition, while the present disclosure has been described above in terms of various exemplary embodiments and implementations, it should be understood that various features and functions described in one or more individual embodiments are not limited to their description as to their applicability to the particular embodiment to which they pertain. Rather, they may be applied to one or more other embodiments of the present disclosure, whether or not such embodiments are described, and whether these features are presented as part of a described embodiment, alone or in some combination. Thus, the breadth and scope of the present disclosure should not be limited by any of the above-described exemplary embodiments.

Fig. 4 is the experimental result of the mechanical property test of the parylene material sample with low surface energy of the present invention.

Claims (7)

1. A low surface energy parylene material characterized by: is formed by chemical vapor deposition of a parylene raw material and a fluorine-containing reagent, the fluorine-containing reagent comprises 2,3, 4,5, 6, 7-dodecafluoro-1, 8-octanediol, 3-trifluoro ethyl propionate nine-carbon perfluoro polyether siloxane, 2-trifluoro ethyl ester perfluoropolyether, 2-trifluoroacetamide, perfluorononane, perfluorodecyl ethyl acrylate, undec fluoro-n-hexane-1-ol, perfluorodecane.

2. The low surface energy parylene material of claim 1, wherein: the difference between the evaporation temperature of the parylene raw material and the evaporation temperature of the fluorine-containing reagent is 0-25 ℃.

3. The low surface energy parylene material of claim 1, wherein: the cleavage temperature of the fluorine-containing reagent is below 700 ℃.

4. A method for preparing a low surface energy parylene material according to claim 1, comprising the steps of:

step 1, placing a parylene raw material and a fluorine-containing reagent into an evaporation chamber;

step 2, vacuumizing the whole reaction device to ensure that the reaction occurs under the vacuum condition;

step 3, firstly raising the temperature of the cracking furnace to 690 ℃ or 650 ℃, and then raising the temperature of the evaporating chamber to 175 ℃;

and 4, depositing a film on the substrate in the room temperature chamber after the raw materials react.

5. The method for preparing the low-surface-energy parylene material according to claim 4, wherein the method comprises the following steps: in said step 1, if the evaporation temperatures of the parylene feedstock and the fluorogenic agent differ by >10 ℃, the parylene feedstock and the fluorogenic agent should be placed separately into the evaporation chamber; if the evaporation temperatures of the parylene material and the fluorine-containing reagent differ by <10 ℃, the parylene material and the fluorine-containing reagent are mixed and placed into an evaporation chamber.

6. The method for preparing the low-surface-energy parylene material according to claim 4, wherein the method comprises the following steps: the base material adopts a metal base plate and needs to be subjected to adhesion performance enhancing treatment.

7. The method for preparing the low-surface-energy parylene material according to claim 4, wherein the method comprises the following steps: the raw materials which cannot be deposited in the step 4 are adhered to a cold well rod at a low temperature through a cold well, and are prevented from entering a vacuum pump.