Anti-fingerprint evaporation AF pill on superhard material surface and preparation method thereof

Abstract

The present application belongs to the field of film-coated evaporation coatings, and specifically relates to an anti-fingerprint evaporation AF pill on the surface of a superhard material and a preparation method thereof. The preparation method comprises: adding a double-ended Z-type perfluoropolyether siloxane and a silane coupling agent to the AF pill, and installing a stainless steel mesh on the surface to separate the steel wool after compacting it. The silane coupling agent is deposited on the surface of the superhard substrate after PVD evaporation, providing a large number of active reaction groups, which undergo hydrolysis and condensation reactions with the end groups of the perfluoropolyether siloxane to form a strong chemical bond, so that the coating has excellent scratch resistance, wear resistance and durability, and improves the durability of the anti-fingerprint effect. The design of the pill particles covers a layer of stainless steel mesh on the steel wool, separating the steel wool that has absorbed the coupling agent and the anti-fingerprint main agent from the outside, reducing the volatilization of the contents while reducing contact with the outside air, reducing the risk of hydrolysis failure, and extending the service life of the pill particles.

Description

Technical Field

[0001] The present application belongs to the field of film-plating evaporation coatings, and specifically relates to an anti-fingerprint evaporation AF pill on the surface of a superhard material and a preparation method thereof. Background Art

[0002] At present, conventional AF (anti-fingerprint) pill particles are mainly divided into two materials: stainless steel and copper. They are in the shape of round cakes and filled with steel wool. A proper amount of PFPE-siloxane (perfluoropolyether siloxane) is added to the steel wool cake to obtain common AF pill particles. The AF pill particles are placed in a vacuum coating device and the perfluoropolyether siloxane is evenly plated on the surface of the glass substrate by evaporation or sputtering to form a coating with anti-fingerprint and friction-resistant effects. Conventional AF pill particles can only have good friction resistance on substrates with relatively low hardness such as glass and plastic, but on ultra-hard substrates such as silicon carbide / anodized metal / stainless steel, there are too few groups on the surface for the main agent to react, resulting in poor durability and wear resistance of the formed coating. After 1,000 times of steel wool friction, the water drop angle is less than 100°. Therefore, the technical problem of how to form a durable and wear-resistant anti-fingerprint coating on an ultra-hard substrate needs to be solved urgently. Summary of the invention

[0003] The present application provides an anti-fingerprint vapor-deposited AF pill on a superhard material surface and a preparation method thereof, aiming to solve to a certain extent the problem that the existing AF pills cannot form a coating with excellent durability and wear resistance and anti-fingerprint and friction effects on a superhard substrate.

[0004] In a first aspect, the present application provides a method for preparing an anti-fingerprint vapor-deposited AF pill on a superhard material surface, comprising the following steps:

[0005] S1, pre-treating the steel wool, placing the steel wool in a sintering furnace for vacuum sintering, annealing and cooling after sintering to obtain sintered steel wool;

[0006] S2, taking pill carrier particles, taking the sintered steel wool and putting it into the pill carrier particles to fill and compact them into a cake shape, and then installing a stainless steel mesh on the pill carrier particles to obtain pill particles;

[0007] S3, adding double-terminal Z-type perfluoropolyether siloxane to the pellet particles obtained in S2, baking the pellet particles after the steel wool cake is fully absorbed, and cooling under set conditions;

[0008] S4, adding silane coupling agent to the pill particles treated in S3, and packaging them to obtain anti-fingerprint vapor-deposited AF pills on the surface of superhard materials.

[0009] Specifically, the vacuum sintering conditions in S1 are: temperature of 480-550° C., vacuum degree of 0.1 MPa-0.5 MPa, and sintering time of 1-2 h.

[0010] Specifically, the annealing cooling conditions in S1 are: after cooling to 50-100° C., take out and place in an environment with a humidity of 5-15% and a temperature of 15-25° C. and continue cooling to room temperature.

[0011] In step S1, the oil, dirt and moisture in the steel wool are removed in a vacuum high-temperature sintering furnace, and at the same time, the steel wool is prevented from oxidation and discoloration under vacuum. The steel wool is first annealed and cooled to 50-100°C in a vacuum sintering furnace, and then placed in a low-temperature and low-humidity environment to cool the steel wool to prevent the steel wool from being oxidized by the high temperature in the air, and also to prevent it from absorbing moisture in the air and affecting the performance of the pill particles.

[0012] In step S2, the steel wool is compacted and then separated by a stainless steel mesh to prevent the small broken strands in the steel wool from escaping into the vacuum coating equipment during the PVD evaporation process and causing risks such as equipment short circuit. At the same time, the evaporation uniformity is controlled during the PVD evaporation process to prevent the high-temperature evaporation of perfluoropolyether siloxane from boiling over to form white spots on the surface of the substrate to be plated, resulting in poor appearance.

[0013] Specifically, the addition amount of the double-terminal Z-type perfluoropolyether siloxane in S3 is 0.2-2 g / particle, and the solid content of the double-terminal Z-type perfluoropolyether siloxane is 20%. Different doses of double-terminal Z-type perfluoropolyether siloxane are added according to the particle size of the pills, different evaporation machine models and wear resistance requirements.

[0014] Specifically, the baking conditions in S3 are: placing in an oven at 50-60° C. and baking for 30-60 minutes.

[0015] Specifically, the cooling condition under the set conditions described in S3 is: placing in an environment with a humidity of 5-15% and a temperature of 15-25° C. and cooling to room temperature.

[0016] In step S3, double-terminal Z-type perfluoropolyether siloxane is selected, considering that this structure has more reactive end groups and can provide more reactive anchor points, thereby improving the wear resistance and durability of the coating. The purpose of adding perfluoropolyether siloxane at low temperature and low humidity under nitrogen protection is to prevent the main agent from hydrolyzing with moisture in the air and causing failure.

[0017] The pill particles after adding 20% ​​perfluoropolyether siloxane are baked in a blast drying oven to remove the solvent, leaving only the main anti-fingerprint component perfluoropolyether siloxane, so that they can be better packaged and transported.

[0018] Specifically, the silane coupling agent in S4 is N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, and the added amount of the silane coupling agent is: 0.5-1% of the total mass of the double-terminal Z-type perfluoropolyether siloxane.

[0019] In step S4, due to the lack of reactive groups on the surface of superhard substrates such as silicon carbide / anodized metal / stainless steel, an appropriate amount of silane coupling agent is added under protective gas after the pill particles are cooled. After PVD evaporation, the silane coupling agent pre-forms a coating on the surface of the superhard substrate, providing a large number of reactive groups for subsequent processes, greatly improving the binding ability of the main agent double-terminal Z-type perfluoropolyether siloxane with the superhard substrate, thereby achieving better wear resistance and durability. The pill particles are vacuum-packed in a clean aluminum foil sealing bag to prevent the hydrolysis of the silane coupling agent and perfluoropolyether siloxane, which can greatly increase the shelf life of the pill particles.

[0020] Silane coupling agents have reactive alkoxy, silyl and other functional groups in their molecules, and have good affinity with the organic functional groups or chemical structures of organic materials. The reaction between silane coupling agents and inorganic materials mainly depends on their hydrolyzable groups, such as methoxy (-OCH 3 ), ethoxy (-OC 2 H 5 ) etc. These groups are hydrolyzed to generate silanol groups (-Si-OH). The silanol groups can react with the hydroxyl groups on the surface of inorganic materials (such as the hydroxyl groups on the surface of glass and metal oxides), thereby forming chemical bonds on the surface of inorganic materials, achieving surface modification of inorganic materials or good bonding with inorganic materials. The other end of the silane coupling agent is an organic functional group that can react with organic materials, the most common of which are amino groups (-NH 2 ), vinyl (-CH=CH 2 ), epoxy group, mercapto group (-SH), etc., react with the corresponding groups in the main agent double-ended Z-type perfluoropolyether siloxane to enhance the overall adhesion. The two end groups are respectively bound to the inorganic matter and the main agent (organic matter), thereby effectively combining the inorganic material and the organic material, thereby improving the adhesion and durability. The method provided by the present invention is mainly to deposit the silane coupling agent on the surface of the superhard substrate after PVD evaporation, provide a large number of active reaction groups, and undergo hydrolysis and condensation reactions with the end groups of perfluoropolyether siloxane to form a strong chemical bond, so that the coating has excellent scratch resistance, wear resistance and durability, and improves the durability of the anti-fingerprint effect.

[0021] The surfaces of superhard materials such as silicon carbide and anodized metals lack reactive active groups such as hydroxyl / carboxyl / amino / epoxy groups. Using perfluoropolyether siloxane alone to deposit on the surface of the substrate through a PVD evaporation process can only provide adhesion through physical adsorption or intermolecular van der Waals forces and electrostatic interactions. However, this intermolecular force is relatively weak, and the coating surface is easily peeled off when subjected to external forces. It cannot provide good wear resistance and durability, and the anti-fingerprint effect of the coating cannot be guaranteed to be long-lasting and durable.

[0022] Due to its high reactivity, silane coupling agent will also cause hydrolysis gel failure when encountering moisture in the air. Stainless steel mesh can effectively reduce direct contact with air. The addition of silane coupling agent to pill particles must be carried out under a nitrogen protection atmosphere, and the humidity in the environment is strictly controlled below 15%. It is also necessary to ensure that the perfluoropolyether siloxane in the particles has been completely dried and adsorbed in the steel wool in a solid state to prevent it from reacting with the silane coupling agent. In addition, the stainless steel mesh in the pill particles can prevent the silane coupling agent and perfluoropolyether siloxane in the particles from boiling during PVD evaporation, and prevent sputtering to the surface of the substrate to form white spots and other poor appearance.

[0023] The selection of silane coupling agent needs to take into account the difference between its boiling point and the boiling point of the anti-fingerprint main agent double-terminal Z-type perfluoropolyether siloxane. The ideal effect to be achieved in the PVD process is that the silane coupling agent is first evaporated and deposited on the surface of the superhard substrate, and then the anti-fingerprint main agent double-terminal Z-type perfluoropolyether siloxane is evaporated to enable it to fully react with the active groups of the silane coupling agent. This requires selecting the type of silane coupling agent according to the evaporation boiling point of the main agent double-terminal Z-type perfluoropolyether siloxane. The double-terminal Z-type perfluoropolyether siloxane (Di-Z-PFPE siloxane) used in the present invention has a molecular weight distribution between 1000 and 100000. Different molecular weight segments have different evaporation boiling points. The molecular weight of the anti-fingerprint main agent double-terminal Z-type perfluoropolyether siloxane selected in the present invention is controlled at 5000-8000, and its boiling point is between 350-480°C. Therefore, the boiling point of the selected silane coupling agent needs to be controlled below 350°C. At the same time, the storage stability of the coupling agent must also be considered. Therefore, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane is preferably selected, and its boiling point is 260°C. In addition, the aminosilane coupling agent becomes very stable in the solution due to the interaction with the amino group, and the storage stability period can be up to 30 days, and there is no need to add a pH adjuster again to ensure its storage stability.

[0024] The double-end Z-type perfluoropolyether siloxane (Di-Z-PFPE siloxane) used in the present invention has a large number of side chains, and the end groups of each side chain fully react with the active groups of the silane coupling agent to form a dense network structure through entanglement and anchoring. The formed anti-fingerprint coating is firmly combined with the surface of the superhard substrate, providing excellent wear resistance and durability.

[0025] In the second aspect, based on the general inventive concept, the present invention also provides a superhard material surface anti-fingerprint evaporation AF pill obtained by the superhard material surface anti-fingerprint evaporation AF pill preparation method as described in the first aspect. The pill particles are covered with a layer of stainless steel mesh on the steel wool to separate the steel wool that absorbs the coupling agent and the anti-fingerprint main agent from the outside, thereby reducing the volatilization of the contents and reducing the contact with the outside air, reducing the risk of hydrolysis failure, and extending the service life of the pill particles. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0027] Figure 1 It is a product diagram prepared by this application;

[0028] Figure 2 This is a commercially available product picture. DETAILED DESCRIPTION

[0029] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0030] In this application, the term "and / or" describes the association relationship of associated objects, indicating that there may be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. A and B can be singular or plural. The character " / " generally indicates that the associated objects are in an "or" relationship.

[0031] In this application, "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can all mean: a, b, c, a~b (i.e. a and b), a~c, b~c, or a~b~c, where a, b, c can be single or multiple, respectively.

[0032] The terms "first" and "second" are used only for descriptive purposes to distinguish objects such as substances from each other, and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. For example, without departing from the scope of the implementation regulations of this application, the first XX may also be referred to as the second XX, and similarly, the second XX may also be referred to as the first XX. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features.

[0033] The terms used in the embodiments of the present application are only for the purpose of describing specific implementation rules, and are not intended to limit the present application. The singular forms "a", "said" and "the" used in the implementation rules of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0034] It should be understood that in the various embodiments of the present application, the size of the serial number of each process does not mean the order of execution, some or all of the steps can be executed in parallel or sequentially, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the implementation regulations of this application.

[0035] The weight of the relevant components mentioned in the embodiment description of the present application can not only refer to the specific content of each component, but also represent the proportional relationship between the weights of the components. Therefore, as long as the content of the relevant components is proportionally enlarged or reduced according to the embodiment description of the present application, it is within the scope disclosed in the embodiment description of the present application. Specifically, the mass described in the embodiment description of the present application can be a mass unit known in the chemical industry such as μg, mg, g, kg, etc.

[0036] Unless otherwise defined, all professional terms used below have the same meanings as those generally understood by those skilled in the art. The professional terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention.

[0037] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in this application can be purchased from the market or prepared by existing methods.

[0038] The technical solution of the present application is illustrated below through specific embodiments and comparative examples.

[0039] In order to enable the above implementation details and operations of the present application to be clearly understood by those skilled in the art, and to significantly demonstrate the improved performance of the embodiments of the present application, the above technical solutions are illustrated by means of multiple embodiments below.

[0040] Example:

[0041] A method for preparing an anti-fingerprint vapor-deposited AF pill on a superhard material surface comprises the following steps:

[0042] S1. Pretreatment of steel wool: placing the steel wool in a sintering furnace for vacuum sintering at a temperature of 500°C, a vacuum degree of 0.2Mpa, and a sintering time of 1.5h. After cooling to 50-100°C, taking it out and placing it in an environment with a humidity of 15% and a temperature of 25°C to continue cooling to room temperature to obtain sintered steel wool;

[0043] S2, taking pill carrier particles, in this embodiment, pill carrier particles with a particle size of 17.8×9 mm are selected, the sintered steel wool is put into the pill carrier particles to fill and compact into a cake shape, and then a stainless steel mesh is installed on the pill carrier particles to obtain pill particles;

[0044] S3, adding double-terminal Z-type perfluoropolyether siloxane with a reinforcement content of 20% to the pellet particles obtained in S2, placing the pellet particles in a 55°C oven for 40 minutes after the steel wool cake is fully absorbed, taking them out and placing them in an environment with a humidity of 15% and a temperature of 25°C to continue cooling to room temperature;

[0045] S4, adding silane coupling agent to the pill particles treated in S3, and packaging them to obtain anti-fingerprint vapor-deposited AF pills on the surface of superhard materials.

[0046] Figure 1 It is a product diagram prepared by this application;

[0047] Figure 2 This is a commercially available product picture.

[0048] 1. Anti-friction performance test: According to the addition amount of double-terminal Z-type perfluoropolyether siloxane as the main agent of pill particles, the effects of different proportions of silane coupling agent on the friction resistance of the coating are compared. The coating substrate selected for the test is anodized aluminum, and the coating is tested for performance after PVD evaporation. The test requirements are: 0000# steel wool (1×1cm) with a load of 1000g, a stroke of 4cm, 60 laps / minute, 3000 laps, an eraser with a load of 1000g, a stroke of 4cm, 40 laps / minute, 3000 laps, and a water drop angle ≥95°.

[0049] 2. Storage stability test: After vacuum packaging, the pill particles were placed in a constant temperature and humidity chamber at 80°C and 80% humidity. After one month of storage, the performance was tested to detect the storage stability of the particles. The results are shown in Table 1.

[0050]

[0051] From the performance test of the above embodiments, it can be known that the most suitable addition amount of silane coupling agent is 0.5-1% of the total mass of the main agent. If the addition amount is too small, the friction performance will not meet the standard. If the addition amount exceeds 1%, the wear resistance will not be significantly improved and the storage stability will decrease, resulting in particle performance failure.

[0052] 3. Silane coupling agent effect test: According to the machine model, the effects of different doses of perfluoropolyether siloxane and different types of silane coupling agents on wear resistance are compared. Taking the United Vacuum 2090 machine as an example, one pill is used per furnace. The coating substrate selected for the test is anodized aluminum. After PVD evaporation, the coating performance is tested. The results are shown in Table 2.

[0053]

[0054] From the above experiments, it can be seen that the amount of double-terminal Z-type perfluoropolyether siloxane used as the main agent of the pill particles determines the friction resistance of the coating. Different types of silane coupling agents have different properties. N-2-(aminoethyl)-3-aminopropyltrimethoxysilane is mainly selected considering the storage stability.

[0055] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0056] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A method for preparing anti-fingerprint evaporation AF pills on the surface of superhard materials, characterized in that: The following steps are involved: S1, pre-treating the steel wool, placing the steel wool in a sintering furnace for vacuum sintering, annealing and cooling after sintering to obtain sintered steel wool; S2, taking pill carrier particles, taking the sintered steel wool and putting it into the pill carrier particles to fill and compact them into a cake shape, and then installing a stainless steel mesh on the pill carrier particles to obtain pill particles; S3, adding double-terminal Z-type perfluoropolyether siloxane to the pellet particles obtained in S2, baking the pellet particles after the steel wool cake is fully absorbed, and cooling under set conditions; S4. Add silane coupling agent to the pill particles treated in S3, and package them to obtain anti-fingerprint vapor-deposited AF pills on the surface of superhard materials. The silane coupling agent is N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, and the addition amount of the silane coupling agent is 0.5-1% of the total mass of the double-terminal Z-type perfluoropolyether siloxane.

2. The preparation method according to claim 1, characterized in that: The vacuum sintering conditions described in S1 are: temperature of 480-550° C., vacuum degree of 0.1 MPa-0.5 MPa, and sintering time of 1-2 h.

3. The preparation method according to claim 1, characterized in that: The annealing cooling conditions in S1 are: after cooling to 50-100° C., take out and place in an environment with a humidity of 5-15% and a temperature of 15-25° C. and continue cooling to room temperature.

4. The preparation method according to claim 1, characterized in that: The addition amount of the double-terminal Z-type perfluoropolyether siloxane in S3 is 0.2-2 g / particle, and the solid content of the double-terminal Z-type perfluoropolyether siloxane is 20%.

5. The preparation method according to claim 1, characterized in that: The baking conditions in S3 are: placing in an oven at 50-60° C. and baking for 30-60 min.

6. The preparation method according to claim 1, characterized in that: The cooling condition under the set conditions described in S3 is: placing in an environment with a humidity of 5-15% and a temperature of 15-25° C. and cooling to room temperature.

7. A superhard material surface anti-fingerprint vapor-deposited AF pill obtained by the method for preparing superhard material surface anti-fingerprint vapor-deposited AF pills as described in any one of claims 1 to 6.

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