Method for modifying polyparaxylylene, polyparaxylylene modified material, and water repellent paint

Abstract

The application relates to the technical field of waterproof materials, in particular to a modification method of poly-p-xylylene, a poly-p-xylylene modified material and a waterproof coating. The modification method of poly-p-xylylene comprises the following steps: mixing raw materials in the presence of oxygen; the raw materials comprise a free radical precursor, poly-p-xylylene particles and a modifying substance; the modifying substance comprises a first modifier. The modification method provided by the application can efficiently introduce hydroxyl groups or isocyanate groups on the skeleton of poly-p-xylylene molecules, effectively improve the proportion of the introduced hydroxyl groups or isocyanate groups on the skeleton of the poly-p-xylylene molecules, further improve the waterproof performance of the modified poly-p-xylylene and enable the modified poly-p-xylylene to be used as a waterproof material, and the application is beneficial to fully recycling the poly-p-xylylene peeled from a deposition chamber.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of waterproof materials, in particular to a modification method of poly-p-xylylene, a poly-p-xylylene modified material and a waterproof coating. BACKGROUND

[0002] The poly-p-xylylene protective material has more excellent protective performance, uniform film forming performance and continuous film forming ability than ordinary three-proofing paint, so that the poly-p-xylylene protective material is one of the most common protective materials in the electronic industry.

[0003] However, there is a big difference between the preparation process of the poly-p-xylylene protective material and the ordinary three-proofing paint, and the poly-p-xylylene protective material can only be formed by depositing the dimeric p-xylene on the surface of the target device (such as electronic device) under vacuum conditions. And the preparation of the poly-p-xylylene protective material needs to be carried out in a deposition chamber, resulting in a large amount of poly-p-xylylene also being deposited and attached to other areas outside the target device in the deposition chamber.

[0004] The poly-p-xylylene sheet peeled off in the deposition chamber has poor waterproof performance and cannot be directly used as a waterproof material, and cannot be fully recycled, thereby causing a large amount of waste of poly-p-xylylene. SUMMARY

[0005] The present application aims to provide a modification method of poly-p-xylylene, a poly-p-xylylene modified material and a waterproof coating, which aims to improve the technical problem that the poly-p-xylylene peeled off from the deposition chamber cannot be fully recycled.

[0006] In a first aspect, the present application provides a modification method of poly-p-xylylene, comprising: mixing raw materials in the presence of oxygen; the raw materials comprising a free radical precursor, poly-p-xylylene particles and a modification substance; the modification substance comprising a first modifier.

[0007] The structure of the effective component in the free radical precursor is as follows:

[0008]

[0009] R1, R2 and R3 are each independently selected from alkyl groups having a C atom number of 2-4.

[0010] The structure of the first modifier is as follows:

[0011]

[0012] m is a natural number greater than or equal to 0, and R4 is a hydroxyl group or an isocyanate group.

[0013] This application involves mixing a free radical precursor, parylene particles, and a modifying substance including a first modifier. In the presence of oxygen, oxygen can insert between the boron (B) atom and the alkyl group (i.e., R1, R2, or R3 group) of the free radical precursor and homolytically cleave to form an alkoxy radical. The formed alkoxy radical has excellent hydrogen-snap-free ability, effectively capturing hydrogen from the parylene molecule. This allows the parylene molecule to covalently bond with the carbon-carbon double bond of the acrylate group in the first modifier molecule, thereby effectively introducing R4 groups (i.e., hydroxyl or isocyanate groups) into the backbone of the parylene molecule. This effectively increases the proportion of R4 groups introduced into the backbone of the parylene molecule, thereby improving the waterproof performance of the modified parylene and enabling its use as a waterproof material. This facilitates the full recycling of parylene stripped from the deposition chamber.

[0014] In some embodiments of the first aspect of this application, the modified substance further includes a second modifier, the structural formula of which is as follows:

[0015]

[0016] n is a natural number ≥ 0, and R5 is a hydroxyl or isocyanate group.

[0017] The raw materials include a first material and a second material; the first material includes a free radical precursor, parylene particles, and a first modifier; the second material includes a second modifier.

[0018] The steps of mixing raw materials include: first mixing the first material, and then mixing the system after the first mixing with the second material.

[0019] Wherein, R4 in the first modifier is a hydroxyl group, and R5 in the second modifier is an isocyanate group; or, R4 in the first modifier is an isocyanate group, and R5 in the second modifier is a hydroxyl group.

[0020] First, the first material is mixed to effectively introduce R4 groups into the backbone of the parylene molecule. Then, the mixed system is mixed with the second material containing the second modifier. Some of the R4 groups on the backbone of the parylene molecule can covalently bond with the R5 groups in the second modifier to the hydroxyl and isocyanate groups. This allows the acrylate groups in the second modifier to also be introduced into the backbone of the parylene molecule. In other words, the backbone of the entire modified parylene molecule contains both R4 groups and acrylate groups, which is beneficial to further improve the waterproof performance of the modified parylene.

[0021] Optionally, the second material also includes a catalyst, which may include N-methylmorpholine or proline.

[0022] The use of a catalyst is beneficial for promoting the covalent bonding reaction between the R4 and R5 groups.

[0023] In some embodiments of the first aspect of this application, the first modifier and the second modifier are each independently selected from at least one of hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, isocyanate ethyl methacrylate, and isocyanate ethyl acrylate.

[0024] Optionally, the first modifier is hydroxyethyl acrylate and the second modifier is ethyl isocyanate acrylate; or, the first modifier is ethyl isocyanate acrylate and the second modifier is hydroxyethyl acrylate.

[0025] Under the above circumstances, it is beneficial to further improve the waterproof performance of the modified parylene.

[0026] In some embodiments of the first aspect of this application, the first material further includes a plasticizer; and / or, the second material further includes a plasticizer.

[0027] The presence of plasticizers in the first and / or second materials helps to form a more homogeneous mixture, facilitating subsequent reactions and processing, and further improving the waterproof performance of the modified poly(p-xylene).

[0028] Optionally, the plasticizer is a mixture containing diethylene glycol dibenzoate and dipropylene glycol dibenzoate.

[0029] In some embodiments of the first aspect of this application, the active ingredient is selected from triethylboron, tripropylboron, or tributylboron.

[0030] The active ingredient is selected from triethylboron, tripropylboron, or tributylboron, which can form alkoxy radicals with strong hydrogen-snap free radicals. This is beneficial to further increase the proportion of R4 groups introduced into the backbone of the parylene molecule, thereby further improving the waterproof performance of the modified parylene.

[0031] Optionally, the free radical precursor includes at least one of triethylboron-1,6-hexanediamine complex and triethylboron-1,3-propanediamine complex; the raw material also includes a decomplexing agent.

[0032] Because triethylboron is flammable and not easy to store and transport directly, it is generally stored in the form of a complex to ensure safety. When the free radical precursor is selected from the complex of triethylboron, a decomplexing agent needs to be added so that triethylboron can be released from the complex system to form ethoxy radicals during the mixing of raw materials.

[0033] Optionally, the decomplexing agent includes at least one of an organic acid or a substance containing an isocyanate group.

[0034] The aforementioned substances can effectively release triethylboron from the complex system.

[0035] Alternatively, the organic acid includes at least one of methacrylic acid, acrylic acid, lactic acid, and acetic acid.

[0036] Optionally, the substance containing an isocyanate group includes at least one of toluene diisocyanate, diphenylmethane diisocyanate, and isophorone diisocyanate.

[0037] In some embodiments of the first aspect of this application, the particle size of the parylene particles is 0.1-40 μm.

[0038] The particle size of parylene particles is 0.1-40μm, which facilitates sufficient mixing and contact between raw materials. This helps to increase the proportion of modified groups (R4 groups, or R4 groups and acrylate groups) introduced into the parylene molecular skeleton, thereby further improving the waterproof performance of the modified parylene.

[0039] In some embodiments of the first aspect of this application, the method for preparing parylene particles includes: first pulverizing the parylene starter to a particle size of 1-20 nm, and then grinding it to a particle size of 0.1-40 μm; wherein an antioxidant is added during the grinding process.

[0040] First, the initial parylene is pulverized to a particle size of 1-20 nm to facilitate subsequent grinding to form particles with a particle size of 0.1-40 μm. Due to the small size after pulverization, the friction and collision between parylene particles are more intense during the grinding process, which will lead to an increase in the temperature of the grinding system. Adding an antioxidant during the grinding process helps to prevent the thermal-oxidative degradation of parylene during the grinding process.

[0041] Optionally, the antioxidant includes at least one of phenolic antioxidants, amine antioxidants, phosphite antioxidants, and thioether antioxidants.

[0042] Alternatively, antioxidants include phenolic antioxidants and thioether antioxidants.

[0043] Antioxidants, including phenolic antioxidants and thioether antioxidants, are beneficial for further improving the resistance of poly(p-xylene) to thermal and oxidative degradation during the grinding process.

[0044] Optionally, the phenolic antioxidant includes at least one of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6-trione, tris(4-tert-butyl-3-hydroxy-2,6-dimethylyl) isocyanurate, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, and 4,6-bis(octylthiomethyl)o-cresol.

[0045] Optionally, thioether antioxidants include at least one of dodecyl thiodipropionate, distearate thiodipropionate, and pentaerythritol tetraester (β-lauryl thiopropionate).

[0046] Optionally, the grinding time is ≤30 min.

[0047] Grinding time ≤ 30 min helps to avoid the system temperature rising due to long grinding time, which would affect the antioxidant’s ability to fully exert its anti-thermal-oxidative degradation performance and reduce the anti-thermal-oxidative degradation effect.

[0048] In some embodiments of the first aspect of this application, the first mixing is carried out by stirring, the first mixing time is 0.5-5 min, and the first mixing speed is 1500-2500 rpm; and / or, the second mixing is carried out by stirring, the second mixing time is 0.5-5 min, and the second mixing speed is 1500-2500 rpm.

[0049] Under the above conditions, it is beneficial to achieve thorough mixing, thereby improving the modification effect of p-paraxylene.

[0050] Secondly, this application provides a parylene-modified material, which is prepared by the parylene modification method provided in the first aspect above.

[0051] The parylene-modified material provided in this application has better waterproof performance and can be used as a waterproof material to improve the waterproof effect of waterproof coatings.

[0052] Thirdly, this application provides a waterproof coating comprising the parylene-modified material as provided in the second aspect above. Attached Figure Description

[0053] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0054] Figure 1 A flowchart of the method for modifying p-p-xylene provided in this application is shown. Detailed Implementation

[0055] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0056] This application provides a method for modifying p-paraxylene. Figure 1 A flowchart of the method for modifying p-paraxylene provided in this application is shown. Please refer to [link / reference]. Figure 1 Methods for modifying p-paraxylene include:

[0057] S10, the initial product of par-xylene is micronized to obtain par-xylene particles.

[0058] Before introducing modified groups (i.e., hydroxyl or isocyanate groups) into the skeleton of parylene, the particle size of parylene is controlled to be 0.1-40 μm. This facilitates sufficient mixing and contact between raw materials during subsequent mixing, which is beneficial to increasing the proportion of modified groups introduced into the parylene molecular skeleton, thereby improving the waterproof performance of the modified parylene.

[0059] As an example, the particles of parylene can be 0.1μm, 0.5μm, 1μm, 5μm, 10μm, 20μm, 25μm or 40μm, etc.

[0060] Furthermore, the preparation method of parylene particles includes: first pulverizing the parylene initial material to a particle size of 1-20 nm, and then grinding it to a particle size of 0.1-40 μm; and adding an antioxidant during the grinding process.

[0061] Because the starting material of parylene is relatively large, it is not easy to directly form particles with a particle size of 0.1-40 μm. Furthermore, during the process of directly forming particles with a particle size of 0.1-40 μm, the system temperature may be high due to inter-particle friction, which may cause some parylene to undergo thermo-oxidative degradation, thus hindering the subsequent modification effect.

[0062] First, the initial parylene is pulverized to a particle size of 1-20 nm to facilitate subsequent grinding to form particles with a particle size of 0.1-40 μm. Due to the small size after pulverization, the friction and collision between parylene particles are more intense during the grinding process, which will lead to an increase in the temperature of the grinding system. Adding an antioxidant during the grinding process helps to prevent thermo-oxidative degradation of parylene due to the high system temperature during the grinding process.

[0063] As an example, in this application, the parylene starting material is parylene sheets directly peeled off from the deposition chamber, which is beneficial for fully recycling the parylene peeled off from the deposition chamber.

[0064] In this application, the mass ratio of pulverized parylene to the antioxidant added during the grinding process is 1:(0.005-0.01). Under these conditions, it is beneficial to further and effectively prevent the thermo-oxidative degradation of parylene.

[0065] In this application, the antioxidant includes at least one of phenolic antioxidants, amine antioxidants, phosphite antioxidants, and thioether antioxidants.

[0066] Phenolic and amine antioxidants primarily act as proton donors to achieve antioxidant effects; phosphite and thioether antioxidants mainly reduce the peroxides generated during the thermal oxidation of parylene, thus protecting it. Furthermore, phenolic, amine, phosphite, and thioether antioxidants all possess certain high-temperature resistance, which helps prevent situations where insufficient heat resistance of the antioxidant itself leads to inadequate protection of parylene.

[0067] As examples, phenolic antioxidants include pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (Irganox 1010, CAS No.: 6683-19-8), 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6-trione (Irganox 3114, CAS No.: 27676-62-6), tris(4-tert-butyl-3-hydroxy-2,6-xylyl) isocyanurate (Irganox 1790, CAS No.: 40601-76-1), and 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene (Irganox) At least one of the following: 1330, CAS No.: 1709-70-2, octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (Irganox 1076, CAS No.: 2082-79-3) and 4,6-bis(octylthiomethyl)o-cresol (Irganox 1520, CAS No.: 110553-27-0).

[0068] Amine antioxidants include at least one of 4,4'-bis(phenylisopropyl)diphenylamine (CAS No.: 10081-67-1), OCTAMINE (CAS No.: 37338-62-8), Antioxidant 5057 (CAS No.: 68411-46-1), and the reaction product of 2-propanone diphenylamine (CAS No.: 68412-48-6).

[0069] Phosphite antioxidants include at least one of tris(2,4-di-tert-butylphenyl) phosphite (CAS No.: 31570-04-4), (2,4-di-tert-butylphenyl) pentaerythritol diphosphite (Irgafos 126, CAS No.: 26741-53-7), tris(nonylphenol) phosphite (CAS No.: 26523-78-4), and dioctadecyl pentaerythritol diphosphite (CAS No.: 3806-34-6).

[0070] Thioether antioxidants include at least one of the following: disodecyl thiodipropionate (Irganox PS800, CAS No.: 123-28-4), distearate thiodipropionate (Naugard DSTDP, CAS No.: 693-36-7), and pentaerythritol tetraester (β-lauryl thiopropionate) (Naugard 412S, CAS No.: 29598-76-3).

[0071] All of the above substances can provide good protection against thermo-oxidative degradation of parylene.

[0072] In this application, the antioxidants are selected from phenolic antioxidants and thioether antioxidants. Phenolic antioxidants are used as the primary antioxidants; thioether antioxidants have better high-temperature resistance than phosphite antioxidants, therefore thioether antioxidants are selected as secondary antioxidants; the synergistic effect of phenolic and thioether antioxidants can further improve the resistance of parylene to thermo-oxidative degradation during the grinding process.

[0073] Furthermore, the antioxidant is selected from phenolic antioxidants and thioether antioxidants, and the phenolic antioxidant is selected from at least one of Irganox 3114, Irganox 1790, Irganox 1330 and Irganox 1076, and the thioether antioxidant is selected from Naugard 412S. The above substances can further improve the protective effect against thermo-oxidative degradation of parylene.

[0074] Furthermore, the phenolic antioxidant is selected from at least one of Irganox 3114, Irganox 1790, and Irganox 1330. These substances have an isocyanate ring and a benzene ring as the central ring of the antioxidant, and thus have higher heat resistance and antioxidant properties.

[0075] In this application, the antioxidant is selected from phenolic antioxidants and thioether antioxidants, and the mass ratio of phenolic antioxidants to thioether antioxidants is 0.5:1.5 to 1.5:0.5. As an example, the mass ratio of phenolic antioxidants to thioether antioxidants is 1:1.

[0076] As an example, the above-mentioned pulverization process can employ a cutting pulverization method or a jaw pulverization method. The above-mentioned grinding process can employ an ultracentrifugal pulverization method, a knife-type mixed grinding method, a mortar grinding method, a disc vibratory grinding method, or a mixed grinding method; furthermore, the above-mentioned grinding process can employ a mixed grinding method or a mortar grinding method.

[0077] Furthermore, a grinding time of ≤30 min helps to avoid the system temperature rising due to a longer grinding time, which would affect the antioxidant's ability to fully exert its anti-thermal-oxidative degradation performance and reduce the anti-thermal-oxidative degradation effect.

[0078] In this application, a plasticizer is added during the grinding process, which helps to make the morphology of the ground parylene particles more uniform and facilitates more thorough mixing with other raw materials in the subsequent mixing process.

[0079] As an example, the plasticizer added during the milling process is a mixture containing diethylene glycol dibenzoate and dipropylene glycol dibenzoate (e.g., benzoflex 2088).

[0080] Furthermore, in this application, the mass ratio of pulverized parylene to plasticizer added during the grinding process does not exceed 1:0.1. As an example, the mass ratio of pulverized parylene to plasticizer added during the grinding process is 1:0.005.

[0081] S20, in the presence of oxygen, a first material containing parylene particles, a free radical precursor and a first modifier is first mixed to obtain a first mixed system.

[0082] The structural formula of the active ingredient in the free radical precursor is as follows:

[0083]

[0084] R1, R2 and R3 are each independently selected from alkyl groups with 2-4 carbon atoms.

[0085] As an example, R1, R2 and R3 are each independently selected from ethyl, propyl and butyl.

[0086] The structural formula of the first modifier is as follows:

[0087]

[0088] m is a natural number ≥ 0, and R4 is a hydroxyl or isocyanate group.

[0089] For example, the value of m can be 0, 1, 2, or 3, etc.

[0090] This application involves mixing a free radical precursor, parylene particles, and a modifying substance including a first modifier. In the presence of oxygen, oxygen can insert between the boron (B) atom and the alkyl group (i.e., R1, R2, or R3 group) of the free radical precursor and homolytically cleave to form an alkoxy radical. The formed alkoxy radical has excellent hydrogen-snap-free ability, effectively capturing hydrogen from the parylene molecule. This allows the parylene molecule to covalently bond with the carbon-carbon double bond of the acrylate group in the first modifier molecule, thereby effectively introducing R4 groups (i.e., hydroxyl or isocyanate groups) into the backbone of the parylene molecule. This effectively increases the proportion of R4 groups introduced into the backbone of the parylene molecule, thereby improving the waterproof performance of the modified parylene and enabling its use as a waterproof material. This facilitates the full recycling of parylene stripped from the deposition chamber.

[0091] Furthermore, during the preparation of parylene protective materials, γ-methacryloxypropyltrimethoxysilane (A174, an adhesion promoter) is typically added during the polymerization of parylene to enhance the overall adhesion of the protective material to the target device. However, A174 has a silanol structure, in which the carbon-oxy-silicon bonds are easily hydrolyzed and unstable. Moreover, silanols readily undergo self-polymerization to produce siloxanes, making it difficult for parylene protective materials to be effectively combined with conventional waterproofing materials. This application addresses this issue by introducing hydroxyl or isocyanate groups into the parylene backbone, enabling parylene to interact and cooperate with conventional waterproofing systems to form waterproof coatings, thereby achieving superior waterproofing performance.

[0092] In this application, the active ingredient in the free radical precursor is selected from triethylboron, tripropylboron, or tributylboron, which can form alkoxy free radicals with strong hydrogen-snap free energy, thereby further increasing the proportion of R4 groups introduced on the backbone of the parylene molecule, and thus further improving the waterproof performance of the modified parylene.

[0093] Furthermore, the active ingredient in the free radical precursor is selected from triethylboron, which can form ethoxy radicals with strong hydrogen-snap radical ability. This is beneficial to further increase the proportion of R4 groups introduced on the backbone of the parylene molecule, thereby further improving the waterproof performance of the modified parylene.

[0094] Because triethylboron is flammable and difficult to store and transport directly, it is generally stored in the form of a complex to ensure safety. Therefore, when the active ingredient in a free radical precursor is selected from triethylboron, the free radical precursor is selected from a triethylboron complex.

[0095] When the radical precursor is selected from a triethylboron complex, the first material also includes a decomplexing agent. The addition of the decomplexing agent allows triethylboron to be released from the complex system to form ethoxy radicals during the mixing process.

[0096] In this application, the free radical precursor includes at least one of triethylboron-1,6-hexanediamine complex and triethylboron-1,3-propanediamine complex. Further, the free radical precursor is selected from triethylboron-1,3-propanediamine complex. The active ingredient in the triethylboron-1,3-propanediamine complex is triethylboron, which can generate ethoxy radicals with good hydrogen-snap radical ability. This is beneficial for increasing the proportion of R4 groups introduced onto the backbone of the poly(p-xylene) molecule. Furthermore, the properties of the complex effectively prevent triethylboron from becoming flammable and explosive, thus improving operational safety.

[0097] In this application, the decomplexing agent includes at least one of an organic acid or a substance containing an isocyanate group. Such substances can effectively release triethylboron from the complexing system.

[0098] Furthermore, the organic acid includes at least one selected from methacrylic acid, acrylic acid, lactic acid, and acetic acid; the substance containing an isocyanate group includes at least one selected from toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), and isophorone diisocyanate (IPDI). These substances can further enhance the decomplexing effect on triethylboron complexes. Even further, the organic acid is selected from methacrylic acid; the substance containing an isocyanate group is selected from IPDI.

[0099] In this application, the first modifier is selected from at least one of hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, isocyanate ethyl methacrylate, and ethyl isocyanate acrylate. These substances can effectively improve the waterproof properties of the modified parylene.

[0100] Furthermore, the first modifier is selected from at least one of hydroxyethyl acrylate and ethyl isocyanate acrylate, which is beneficial to further improve the waterproof performance of the modified poly(p-xylene).

[0101] In this application, the first material also includes a plasticizer, which helps to form a more homogeneous mixture after the first mixture is mixed, facilitating subsequent reactions and processing, and further improving the waterproof performance of the modified poly(p-xylene).

[0102] As an example, the plasticizer in the first material is a mixture containing diethylene glycol dibenzoate and dipropylene glycol dibenzoate (e.g., benzoflex 2088).

[0103] In this application, the mass ratio of parylene particles, free radical precursor, decomplexing agent, first modifier, and plasticizer in the first material is 100:(2-7):(2-7):(2-8):(5-15). As an example, the mass ratio of parylene particles, free radical precursor, decomplexing agent, first modifier, and plasticizer in the first material is 100:2:2:5:10.

[0104] In this application, the first mixing is carried out by stirring, the first mixing time is 0.5-5 min, and the first mixing speed is 1500-2500 rpm; under the above conditions, it is beneficial to achieve thorough mixing, thereby improving the modification effect of p-paraxylene.

[0105] In this application, after the first mixing, the mixture needs to be left to stand at room temperature for 0.5-24 hours to allow for sufficient modification. Furthermore, after the first mixing, it needs to be left to stand at room temperature for 2-3 hours.

[0106] S30, the first mixture system is mixed with the second material containing the second modifier in a second mixing.

[0107] The structural formula of the second modifier is as follows:

[0108]

[0109] n is a natural number ≥ 0, and R5 is a hydroxyl or isocyanate group.

[0110] For example, the value of m can be 0, 1, 2, or 3, etc.

[0111] Wherein, when R4 in the first modifier in step S20 is a hydroxyl group, R5 in the second modifier in step S30 is an isocyanate group; or, when R4 in the first modifier in step S20 is an isocyanate group, R5 in the second modifier in step S30 is a hydroxyl group.

[0112] First, the first material is mixed (i.e., step S20), which allows R4 groups to be effectively introduced into the backbone of the parylene molecule. Then, the system after the first mixture is mixed with the second material containing the second modifier (i.e., step S30). Some of the R4 groups on the backbone of the parylene molecule can covalently bond with the R5 groups in the second modifier to hydroxyl and isocyanate groups, thereby allowing the acrylate groups in the second modifier to also be introduced into the backbone of the parylene molecule. That is, the backbone of the entire modified parylene molecule contains both R4 groups and acrylate groups, which is beneficial to further improve the waterproof performance of the modified parylene.

[0113] In this application, the first modifier is hydroxyethyl acrylate, and the second modifier is ethyl isocyanate acrylate; or, the first modifier is ethyl isocyanate acrylate, and the second modifier is hydroxyethyl acrylate. In these cases, it is beneficial to further improve the waterproof performance of the modified parylene.

[0114] Furthermore, the second material also includes a catalyst for promoting the covalent bonding reaction between the R4 and R5 groups. As an example, the catalyst is selected from N-methylmorpholine or proline.

[0115] It should be noted that, in other feasible implementations, the catalyst may also be a cyclic compound containing nitrogen.

[0116] The second material also includes a plasticizer, which helps to form a more homogeneous mixture after the second mixing, facilitating subsequent reactions and processing.

[0117] As an example, the plasticizer in the second material is a mixture containing diethylene glycol dibenzoate and dipropylene glycol dibenzoate (e.g., benzoflex 2088).

[0118] In this application, the second mixing is carried out by stirring, the second mixing time is 0.5-5 min, and the second mixing speed is 1500-2500 rpm; under the above conditions, it is beneficial to achieve thorough mixing, thereby improving the modification effect of p-paraxylene.

[0119] In this application, after the second mixing, the mixture needs to be left to stand at room temperature for 0.5-24 hours to allow for sufficient modification. Furthermore, after the second mixing, it needs to be left to stand at room temperature for 2-3 hours.

[0120] It should be noted that in this application, steps S20 and S30 can be performed continuously or intermittently, or only step S20 can be performed without step S30. The scheme of "performing both steps S20 and S30" can further improve the waterproof performance of the modified parylene compared to the scheme of "performing only step S20".

[0121] This application also provides a parylene-modified material, which is prepared by the parylene modification method provided above.

[0122] The parylene-modified material provided in this application has better waterproof performance and can be used as a waterproof material to improve the waterproof effect of waterproof coatings.

[0123] This application also provides a waterproof coating comprising the parylene-modified material as provided in the second aspect above.

[0124] The waterproof coating provided in this application has a superior waterproofing effect.

[0125] Example 1

[0126] This embodiment provides a poly(p-xylene) modified material and its preparation method, which is prepared by the following steps:

[0127] (1) Cut 200g of parylene film into rectangular blocks with a size of 17cm*20cm. Place the cut block samples into a cutting pulverizer and pulverize for 5 minutes. Then sieve the parylene pulverized material with a size of 5mm or smaller.

[0128] (2) Place the 190g of parylene pulverized material obtained in step (1) into a disc vibratory mill and add 1.9g of antioxidant packet (the antioxidant packet consists of 0.95g of benzoflex2088, 0.475g of Irganox 1790, and 0.475g of Naugard 412S). Grind for 20min and sieve out parylene particles of 25μm and below.

[0129] (3) Place 100g of poly(p-xylene) particles, 2g of triethylboron-1,6-hexanediamine complex, 2g of methacrylic acid, 5g of hydroxyethyl acrylate and 10g of benzoflex 2088 into a planetary stirrer and stir at 2000rpm for 2min, then let stand at room temperature for 2h.

[0130] (4) Add 6.1g of ethyl isocyanate acrylate and 0.1g of N-methylmorpholine to the mixture in step (3), stir and mix at 2000rpm for 2min in a planetary stirrer, and then let stand at room temperature for 2h.

[0131] Example 2

[0132] This embodiment provides a poly(p-xylene) modified material and its preparation method. The difference between this embodiment and Embodiment 1 is that step (4) is not performed.

[0133] Example 3

[0134] This embodiment provides a poly(p-xylene) modified material and its preparation method. The difference between this embodiment and Example 1 is that 5g of hydroxyethyl acrylate in step (3) is replaced with 6.1g of ethyl isocyanate acrylate, and step (4) is not performed.

[0135] Example 4

[0136] This embodiment provides a poly(p-xylene) modified material and its preparation method. The difference between this embodiment and Example 1 is that the ethyl isocyanate in step (4) is replaced with ethyl isocyanate methacrylate.

[0137] Example 5

[0138] This embodiment provides a poly(p-xylene) modified material and its preparation method. The difference between this embodiment and Example 1 is that the hydroxyethyl acrylate in step (3) is replaced with hydroxybutyl acrylate.

[0139] Example 6

[0140] This embodiment provides a poly(p-xylene) modified material and its preparation method. The difference between this embodiment and Example 1 is that the 25 μm in step (2) is changed to 50 μm.

[0141] Example 7

[0142] This embodiment provides a poly(p-xylene) modified material and its preparation method. The difference between this embodiment and Embodiment 1 is that Naugard 412S in step (2) is replaced with Irgafos 126.

[0143] Example 8

[0144] This embodiment provides a poly(p-xylene) modified material and its preparation method. The difference between this embodiment and Embodiment 1 is that Irganox 1790 in step (2) is replaced with OCTAMINE.

[0145] Comparative Example 1

[0146] This comparative example provides a poly(p-xylene) modified material and its preparation method, which is prepared by the following steps:

[0147] (1) Cut 200g of parylene film into rectangular blocks with a size of 17cm*20cm. Place the cut block samples into a cutting pulverizer and pulverize for 5 minutes. Then sieve the parylene pulverized material with a size of 5mm or smaller.

[0148] (2) Place the 190g of parylene pulverized material obtained in step (1) into a disc vibratory mill and add 1.9g of antioxidant packet (the antioxidant packet consists of 0.95g of benzoflex2088, 0.475g of Irganox 1790, and 0.475g of Naugard 412S). Grind for 20min and sieve out parylene particles of 25μm and below.

[0149] (3) Place 100g of parylene granules, 2g of benzoyl peroxide, 5g of hydroxyethyl acrylate, and 10g of benzoflex 2088 obtained in step (2) into a planetary stirrer and mix at 2000rpm for 2min. Then, use a dispersion plate to stir and add 0.5g of N,N-dimethyl-p-toluidine, and stir for 2 hours.

[0150] Comparative Example 2

[0151] This comparative example provides a poly(p-xylene) modified material and its preparation method. The difference between this comparative example and Example 1 is that steps (3) and (4) are not performed.

[0152] Test case

[0153] Waterproof coatings were prepared using parylene-modified materials obtained in Examples 1-8 and Comparative Examples 1-2, respectively. The salt spray resistance, water vapor permeability coefficient and dielectric constant of the prepared waterproof coatings were tested, and the test results are shown in Table 1.

[0154] The preparation method of the waterproof coating is as follows: at room temperature, 59g of isobornyl acrylate (IBOA), 1g of N-methylmorpholine, 35.8g of poly(p-xylene) modifier, 2g of Irgacure 1173 (CAS No.: 7473-98-5), 0.15g of 2,6-di-tert-butyl-p-cresol (BHT), 0.05g of benzoquinone, and 2g of acrylate phosphate are stirred and mixed evenly.

[0155] The method for determining salt spray resistance is as follows: Apply a waterproof coating to the surface of a copper plate with a coating thickness of 100 μm. Test the salt spray resistance according to ASTM B117. After 1000 hours, remove the copper plate from the salt spray test and immediately wash it with hot water. Clean and dry the surface of the copper plate and observe its appearance according to ASTM D714-87.

[0156] Table 1

[0157]

[0158] Note: In Table 1, the degree of bubbling is: more bubbles > bubbles > slight bubbles > no bubbles.

[0159] As can be seen from Table 1, the water vapor transmission rate of waterproof coatings prepared using the parylene-modified materials obtained in Examples 1-8 is lower than that of waterproof coatings prepared using the parylene-modified materials obtained in Comparative Examples 1-2. This indicates that the modification method provided in this application, compared with the benzoyl peroxide modification method in Comparative Example 1 and the method in Comparative Example 2 without group modification of parylene particles, can effectively reduce the water vapor transmission rate of waterproof coatings, thereby improving the waterproof effect.

[0160] A comparison of Examples 1-3 shows that, compared to Example 2 which only modified hydroxyl groups and Example 3 which only modified isocyanate groups, Example 1, by modifying both hydroxyl and isocyanate groups sequentially, is beneficial in further reducing the water vapor permeability of the waterproof coating. Compared to Example 2 which only modified hydroxyl groups, Example 3, by modifying only isocyanate groups, allows ethyl isocyanate acrylate to have a post-curing effect. Under the influence of water vapor, the isocyanate groups (-NCO) are ultimately converted into a polyurea structure with better waterproof performance.

[0161] A comparison between Example 1 and Example 4 shows that the use of ethyl isocyanate in Example 1, compared to the use of isocyanate methacrylate in Example 4, is beneficial in further reducing the water vapor permeability of the waterproof coating. This is because the acrylate groups in the ethyl isocyanate in Example 1 have a better curing effect under the same light curing conditions than the methacrylate groups in the isocyanate methacrylate in Example 4.

[0162] A comparison between Example 1 and Example 5 shows that the use of hydroxyethyl acrylate in Example 1, compared to the use of hydroxybutyl acrylate in Example 5, can slightly reduce the water vapor permeability of the waterproof coating.

[0163] A comparison between Example 1 and Example 6 shows that the particle size of parylene particles in Example 1 is smaller than that in Example 6, which makes the waterproof coating prepared in Example 1 more compact and helps to further reduce the water vapor permeability of the waterproof coating.

[0164] The comparison of Examples 1 and 7-8 shows that Naugard 412S can further reduce the water vapor permeability of the waterproof coating compared to Irgafos 126, and Irganox 1790 can further reduce the water vapor permeability of the waterproof coating compared to OCTAMINE. This indicates that Naugard 412S has better high-temperature resistance and antioxidant properties than Irgafos 126, and Irganox 1790 has better high-temperature resistance and antioxidant properties than OCTAMINE. During the grinding of parylene pulverized material, the decomposition caused by thermo-oxidative aging of parylene is effectively avoided, which is beneficial to improving the overall waterproof performance.

[0165] In summary, the modification method provided in this application can effectively introduce modified groups into the backbone of parylene molecules, thereby improving the waterproof performance of the modified parylene and enabling it to be used as a waterproof material. This is beneficial for the full recycling of parylene stripped from the deposition chamber.

[0166] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for modifying polyparaxylylene characterized in that, The method comprises: mixing raw materials in the presence of oxygen; the raw materials comprise a radical precursor, poly-p-xylylene particles, and a modifying substance; the modifying substance comprises a first modifier and a second modifier; wherein the effective component in the radical precursor has a structure as follows: R1, R2, and R3 are each independently selected from alkyl groups with a C atom number of 2-4; the first modifier has a structure as follows: m is a natural number greater than or equal to 0; the second modifier has a structure as follows: n is a natural number greater than or equal to 0; wherein R4 in the first modifier is a hydroxyl group, and R5 in the second modifier is an isocyanate group; or, R4 in the first modifier is an isocyanate group, and R5 in the second modifier is a hydroxyl group.

2. The modification method according to claim 1, characterized by, The raw materials comprise a first material and a second material; the first material comprises the radical precursor, the poly-p-xylylene particles, and the first modifier; the second material comprises the second modifier; The step of mixing the raw materials comprises: first mixing the first material, and then second mixing the first mixed system with the second material.

3. The modification method according to claim 2, wherein The second material further comprises a catalyst selected from N-methylmorpholine or proline.

4. The modification method according to claim 2, wherein The first modifier and the second modifier are each independently selected from at least one of hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, isocyanatoethyl methacrylate, and isocyanate acrylate ethyl ester.

5. The modification method according to claim 4, wherein The first modifier is hydroxyethyl acrylate, and the second modifier is isocyanate acrylate ethyl ester; or, the first modifier is isocyanate acrylate ethyl ester, and the second modifier is hydroxyethyl acrylate.

6. The modification method of claim 2, wherein, The first material further comprises a plasticizer; and / or, the second material further comprises a plasticizer.

7. The modification method according to claim 6, wherein The plasticizer is a mixture containing diethylene glycol dibenzoate and dipropylene glycol dibenzoate.

8. The modification method of claim 1, wherein, The effective component is selected from triethyl boron, tripropyl boron, or tributyl boron.

9. The modification method according to claim 8, characterized in that, The radical precursor comprises at least one of triethyl boron-1,6-hexanediamine complex and triethyl boron-1,3-propanediamine complex; the raw materials further comprise a decomplexing agent.

10. The modification method according to claim 9, wherein The decomplexing agent comprises at least one of an organic acid or a substance containing an isocyanate group.

11. The modification method of claim 10, wherein, The organic acid comprises at least one of methacrylic acid, acrylic acid, lactic acid, and acetic acid.

12. The modification method of claim 10, wherein, The substance containing an isocyanate group comprises at least one of toluene diisocyanate, diphenyl methane diisocyanate, and isophorone diisocyanate.

13. The modification method of claim 1, wherein, The poly-p-xylylene particles have a particle size of 0.1-40 μm.

14. The modification method of claim 13, wherein, The preparation method of the poly-p-xylylene particles comprises: first crushing poly-p-xylylene initial material to a particle size of 1-20 mm, and then grinding to a particle size of 0.1-40 μm; wherein an antioxidant is added during the grinding process.

15. The method of modifying of claim 14, wherein, The antioxidant comprises at least one of a phenolic antioxidant, an amine antioxidant, a phosphite antioxidant, and a sulfide antioxidant.

16. The method of modifying of claim 14, wherein, The antioxidant comprises a phenolic antioxidant and a sulfide antioxidant.

17. The modification method according to claim 15 or 16, characterized in that, The phenolic antioxidant includes at least one of tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid]pentaerythritol ester, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazinane-2,4,6-trione, isocyanuric acid tri(4-tert-butyl-3-hydroxy-2,6-dimethylphenyl) ester, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, and 4,6-bis(octylthiomethyl)orthocresol.

18. The modification method according to claim 15 or 16, characterized by, The sulfide antioxidant includes at least one of dilauryl thiodipropionate, distearyl thiodipropionate, and pentaerythritol tetra(β-laurylthiopropionate).

19. The method of modifying of claim 14, wherein, The grinding time is ≤30 min.

20. The method of modifying of claim 2, wherein, The first mixing is stirring mixing, the first mixing time is 0.5-5 min, and the first mixing speed is 1500-2500 rpm. The second mixing is stirring mixing, the second mixing time is 0.5-5 min, and the second mixing speed is 1500-2500 rpm.

21. A parylene-modified material, characterized by, The parylene-modified material is prepared by the method for modifying parylene according to any one of claims 1-20.

22. A water repellent coating, characterized by The parylene-modified material is prepared by the method for modifying parylene according to any one of claims 1-20.

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