A tri-proof paint and a preparation method thereof

Abstract

The application belongs to the technical field of three-proofing paint and particularly relates to a three-proofing paint and a preparation method thereof, raw materials of the three-proofing paint comprising a reaction monomer containing an acrylic group, a surface improvement additive, and an oligomer, the surface improvement additive comprising a vinyl MQ silicone resin and / or polymethyl methacrylate; and the amount of the oligomer accounting for 15wt%-45wt% of the total amount of the raw materials, and the mass ratio of the oligomer to the surface improvement additive being 1:(0.011-0.533). The three-proofing paint has low water vapor permeability and low oxygen inhibition, and has comprehensive performance, so as to improve the moisture-proof, salt mist-proof and mildew-proof performance.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of three-proofing paint, and particularly relates to a three-proofing paint and a preparation method thereof. BACKGROUND

[0002] With the development of China's industrial technology in the fields of deep sea, deep space, deep land and deep blue, electronic products are often exposed to high temperature, vibration, humidity, salt spray, sand and other harsh environments, and the reliability of electronic products faces severe challenges. Organic coating protection technology is one of the effective strategies to improve the reliability of electronic products, which has the characteristics of low cost, easy processing and excellent protection performance. According to the curing process, the organic coating protection technology can be divided into thermal curing type, ultraviolet light curing type and moisture curing type. Among them, the thermal curing type needs to heat the electronic product and has high energy consumption, the ultraviolet light curing type has extremely fast curing speed but has the problem of uneven curing, and the moisture curing type has slow curing speed. In order to solve the defects of the above curing processes and improve the protection performance of the coating, researchers realize the effective protection of electronic products through the research and innovation of oligomers.

[0003] In recent years, the research and innovation of oligomers have become an important way to improve the organic coating protection technology. As one of the important components of coating, oligomers are composed of functional groups and main chains that can realize different curing processes, and can be divided into epoxy acrylate oligomers, polyurethane acrylate oligomers and polyester acrylate oligomers according to the different main chain structures. The surface curing process of the three-proofing paint prepared by the oligomers is obviously affected by the oxygen inhibition phenomenon. The oxygen inhibition phenomenon refers to that the free radicals are generated after the photoinitiator is irradiated in the UV curing oven, the free radicals react with the acrylic acid groups to promote the curing film formation, but the free radicals on the surface of the film react with the oxygen in the air to form the structure of free radical-O-O, which hinders the surface curing process and consumes the content of the surface free radicals, resulting in incomplete surface curing of the three-proofing paint. Therefore, the surface oxygen inhibition is serious, the surface curing is incomplete, and the three-proofing paint sample surface has the characteristics of high viscosity and more serious un-cured liquid on the surface. In addition, the moisture resistance, salt spray resistance and mildew resistance of the three-proofing paint are general. However, with the increasingly harsh application scenarios of electronic products, the above traditional oligomers cannot meet the performance protection requirements of electronic products such as moisture resistance, salt spray resistance and mildew resistance. Therefore, it is of great practical significance and urgent need to research and innovate oligomers and develop three-proofing curing coatings with higher protection performance.

[0004] It should be noted that this part of the application only provides background technology related to the application, and does not necessarily constitute prior art or public knowledge. SUMMARY

[0005] The present application aims to overcome the defects of the prior art, such as high water vapor transmission rate, obvious oxygen inhibition in surface curing process, and poor three-proofing performance such as moisture-proof, salt mist-proof, and mildew-proof, and provides a three-proofing coating and a preparation method thereof, which has low water vapor transmission rate and low oxygen inhibition, thereby improving the moisture-proof, salt mist-proof, and mildew-proof performance.

[0006] To achieve the above-mentioned purpose, in a first aspect, the present application provides a three-proofing coating, raw materials of which include: a reaction monomer containing an acrylic group, a surface improvement aid, and an oligomer; the surface improvement aid includes vinyl MQ silicone resin and / or polymethyl methacrylate; and the amount of the oligomer accounts for 15wt%-45wt% of the total amount of the raw materials, and the mass ratio of the oligomer to the surface improvement aid is 1:(0.011-0.533); wherein the oligomer has the following general formula:

[0007] n=40-250.

[0008] Preferably, the average molecular weight of the oligomer is 3000-15000 g / mol, and the dynamic viscosity at 25°C is 1000000-3500000 cp.

[0009] In some preferred embodiments of the present application, when the water vapor transmission amount of the three-proofing coating after being coated to a thickness of 50μm under the condition of 38°C and 90% RH is below 15g / (m 2 ·24h), the amount of the oligomer accounts for 30-45wt%.

[0010] In some preferred embodiments of the present application, when the water vapor transmission amount of the three-proofing coating after being coated to a thickness of 50μm under the condition of 38°C and 90% RH is greater than 15g / (m 2 ·24h), the amount of the oligomer accounts for 15-29wt%.

[0011] In some preferred embodiments of the present application, the amount of the surface improvement aid accounts for 0.5wt%-8wt% of the total amount of the raw materials.

[0012] In some preferred embodiments of the present application, the surface improvement aid includes vinyl MQ silicone resin, the average molecular weight of the vinyl MQ silicone resin is 6000-8000 g / mol, and the amount of the vinyl MQ silicone resin accounts for 0.5wt%-3wt% of the total amount of the raw materials.

[0013] In some preferred embodiments of the present application, the surface improvement aid includes polymethyl methacrylate, the average molecular weight of the polymethyl methacrylate is 10000-50000 g / mol, and the amount of the polymethyl methacrylate accounts for 2wt%-8wt% of the total amount of the raw materials.

[0014] In some preferred embodiments of the present application, the ratio of the average molecular weight of the oligomer to the poly(methyl methacrylate) is 1:(0.67-16.67).

[0015] In some preferred embodiments of the present application, the total amount of the reaction monomer added is 30wt%-65wt% based on the total amount of the raw materials, and / or the mass ratio of the oligomer to the reaction monomer is 1:(0.67-4.33).

[0016] In some preferred embodiments of the present application, the reaction monomer comprises at least one of a monofunctional reaction monomer, a bifunctional reaction monomer, and a trifunctional reaction monomer, the amount of the monofunctional reaction monomer is 0wt%-65wt% based on the total amount of the raw materials, the amount of the bifunctional reaction monomer is 0wt%-65wt% based on the total amount of the raw materials, the amount of the trifunctional reaction monomer is 0wt%-65wt% based on the total amount of the raw materials, and the amounts of the monofunctional reaction monomer, the bifunctional reaction monomer, and the trifunctional reaction monomer are not all zero.

[0017] In some preferred embodiments of the present application, the monofunctional reaction monomer comprises at least one of isobornyl acrylate, dicyclopentenyl acrylate, lauryl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and isooctyl acrylate; the bifunctional reaction monomer comprises 1,6-hexanediol diacrylate and / or tricyclodecane dimethanol diacrylate; and the trifunctional reaction monomer comprises trimethylolpropane triacrylate.

[0018] Further preferably, the monofunctional reaction monomer comprises dicyclopentenyl acrylate.

[0019] In some preferred embodiments of the present application, when it is required to adjust the water vapor transmission rate of the three-proofing coating after being coated to a thickness of 50μm under the condition of 38℃, 90%RH to be less than or equal to 15g / (m 2 ·24h), the reaction monomer comprises at least one of isobornyl acrylate, dicyclopentenyl acrylate, and tricyclodecane dimethanol diacrylate; and when it is required to adjust the water vapor transmission rate of the three-proofing coating after being coated to a thickness of 50μm under the condition of 38℃, 90%RH to be greater than 15g / (m 2 ·24h), the reaction monomer comprises butyl acrylate and / or 2-ethylhexyl acrylate.

[0020] In some preferred embodiments of the present application, the raw materials of the three-proofing coating further comprise a photoinitiator, wherein the mass ratio of the oligomer to the photoinitiator is 1:(0.05-2.67); and / or the amount of the photoinitiator is 3wt%-10wt%.

[0021] In some preferred embodiments of the present application, the raw materials of the tri-proof paint further comprise at least one of a polymerization inhibitor, an adhesion promoter, and a fluorescent whitening agent, wherein the amount of the polymerization inhibitor is 0.01wt%-0.1wt% based on the total amount of the raw materials, the amount of the adhesion promoter is 0-1.5wt% based on the total amount of the raw materials, and the amount of the fluorescent whitening agent is 0.005wt%-0.05wt% based on the total amount of the raw materials.

[0022] In some preferred embodiments of the present application, when the tri-proof paint needs to be subjected to UV and moisture dual curing, the raw materials of the tri-proof paint further comprise at least one of methyl cyanoacrylate, butyl cyanoacrylate, acetic acid, and methacrylic acid, wherein the total amount of the methyl cyanoacrylate and the butyl cyanoacrylate is 0-3wt% based on the total amount of the raw materials, and the total amount of the acetic acid and the methacrylic acid is 0-0.1wt% based on the total amount of the raw materials.

[0023] In a second aspect, the present application provides a preparation method of a tri-proof paint, which is used for preparing the tri-proof paint of the first aspect, and the preparation method comprises:

[0024] mixing the reaction monomer comprising an acrylic group and the oligomer having an acrylic group-terminated and a polyisobutylene skeleton structure to obtain a first mixed solution;

[0025] adding optional additives comprising at least one of a photoinitiator, a polymerization inhibitor, an adhesion promoter, and a fluorescent whitening agent to the first mixed solution to obtain a second mixed solution;

[0026] then introducing a surface improvement additive to obtain a third mixed solution.

[0027] In some preferred embodiments of the present application, the first mixing is performed in a planetary mixer at a rotation speed of 1800-2400 r / min for 100-200 s, and the first mixing is repeated for 1-5 times.

[0028] In some preferred embodiments of the present application, the second mixing is performed in a planetary gear mixer at a rotation speed of 1800-2400 r / min for 100-200 s, and the second mixing is repeated for 1-5 times.

[0029] In some preferred embodiments of the present application, the third mixing is performed in a planetary gear mixer at a rotation speed of 1800-2400 r / min for 100-200 s.

[0030] In some preferred embodiments of the present application, when the tri-proof paint needs to be subjected to UV and moisture dual curing, the preparation method further comprises: introducing acetic acid and / or methacrylic acid to the third mixed solution obtained by the third mixing to obtain a fourth mixed solution, and then introducing methyl cyanoacrylate and / or butyl cyanoacrylate to obtain a fifth mixed solution.

[0031] In some preferred embodiments of the present invention, the conditions for the fourth and fifth mixing each independently include: being carried out in a planetary gear mixer at a speed of 1800-2400 r / min and a mixing time of 100-200 s.

[0032] Beneficial effects:

[0033] This invention, through the above-mentioned technical solution, particularly the use of acrylic acid groups for end-capping and polyisobutylene as the backbone structure in a specific general formula oligomer, produces oligomers with characteristics such as high viscosity, high flexibility, high water vapor barrier properties, water resistance, acid and alkali resistance, and heat resistance. Combined with the addition of appropriate amounts of specific surface-improving additives, "vinyl MQ resin and / or polymethyl methacrylate," the acrylic acid groups in polymethyl methacrylate participate in the photocuring process and react with the oligomers and reactive monomers. The C=C bonds in vinyl MQ silicone resin can react with free radicals, and the reaction products further participate in the curing process of the acrylic acid groups in the oligomers (the reaction process is exemplified by vinyl MQ resin; the reaction without vinyl MQ resin is shown in Formula 1, and the reaction with vinyl MQ resin is shown in Formula 1). The reaction after resin formation is shown in Formula 2. The organosilicon structure in vinyl MQ silicone resin and the methacrylic acid groups in polymethyl methacrylate can effectively isolate oxygen and reduce oxygen inhibition, thereby effectively improving the oxygen inhibition situation. This is beneficial to effectively reduce the elasticity of specific oligomers after curing, reduce the surface oxygen inhibition level, and reduce water vapor transmission. In addition, the addition of reactive monomers containing acrylic acid groups can react with oligomers containing isocyanate groups, vinyl MQ resin and / or polymethyl methacrylate, which helps to reduce viscosity and increase crosslinking density. As a result, the conformal coating has low water vapor transmission, good moisture-proof, salt spray-proof, mildew-proof performance, and extremely low oxygen inhibition, making it suitable for situations with higher requirements for conformal performance.

[0034] Formula 1

[0035] Equation 2.

[0036] The application also controls the amount of the oligomer and the mass ratio of the oligomer to the surface improvement aid to be in a suitable range respectively, so that the surface improvement aid and the oligomer and the curing reaction of the reaction monomer form a dense sufficient curing, ensures the surface curing effect of the three-proofing paint, and the specific skeleton structure of the surface improvement aid and the skeleton structure distribution of the oligomer in the reaction product are close, which is more beneficial to effectively isolate oxygen and effectively reduce the negative influence of oxygen inhibition, thereby improving the performance of the three-proofing paint and reducing dust adsorption. Under the same conditions, if the mass ratio of the oligomer to the surface improvement aid is too large, the surface viscosity of the three-proofing paint after curing will increase or even un-cured phenomenon will occur, and if the mass ratio is too small, the protection performance of the three-proofing paint product will be reduced, and the oxygen inhibition performance cannot be effectively improved. DETAILED DESCRIPTION

[0037] In the present application, the terms "first", "second" are used only for descriptive purposes and should not be construed as indicating or implying relative importance or an indicated number of technical features. Therefore, the features defined as "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise specifically limited.

[0038] The endpoints of the ranges and any values disclosed herein are not limited to the precise values stated. The ranges or values should be construed to be roughly about the ranges. Individual endpoints of the ranges, the individual endpoints and single point values between the endpoints of the ranges, and the single point values can be combined with each other to form one or more new ranges, which should be considered to be specifically disclosed herein. Among them, the terms "optional", "optional" mean that it can be included, or it can not be included (or it can be, or it can not be).

[0039] In a first aspect, the present application provides a three-proofing paint, which raw materials include: a reaction monomer containing an acrylic group, a surface improvement aid, and an oligomer, the surface improvement aid includes vinyl MQ silicone resin and / or polymethyl methacrylate; and the amount of the oligomer accounts for 15wt%-45wt% of the total amount of the raw materials, and the mass ratio of the oligomer to the surface improvement aid is 1:(0.011-0.533), preferably 1:(0.011-0.090), and further 1:(0.011-0.090).

[0040] The oligomer has the following general formula:

[0041] n=40-250.

[0042] Preferably, the average molecular weight of the oligomer is 3000-15000 g / mol, and / or the dynamic viscosity of the oligomer at 25℃ is 1000000-3500000 cp. The use of oligomers with suitable average molecular weight and dynamic viscosity is conducive to improving process applicability and processing.

[0043] In some preferred embodiments of the present application, the amount of oligomer is 30-45 wt% when the water vapor transmission rate of the three-proofing coating after being coated to a thickness of 50μm under the condition of 38℃, 90% RH is below 15g / (m 2 ·24h).

[0044] In some preferred embodiments of the present application, the amount of oligomer is 15-29 wt% when the water vapor transmission rate of the three-proofing coating after being coated to a thickness of 50μm under the condition of 38℃, 90% RH is greater than 15g / (m 2 ·24h).

[0045] For three-proofing coatings with different water vapor transmission rate requirements, the present application controls the amount of oligomer within the above suitable range, which is conducive to adjusting the viscosity of the product and effectively improving the oxygen inhibition phenomenon, thereby improving the moisture-proof, salt-fog-proof and mildew-proof performance.

[0046] In some preferred embodiments of the present application, the amount of surface improvement aid is 0.5wt%-8wt% based on the total amount of raw materials, and can be specifically, for example, 0.5wt%, 1wt%, 1.5wt%, 2wt%, 2.5wt%, 3wt%, 3.5wt%, 4wt%, 4.5wt%, 5wt%, 5.5wt%, 6wt%, 6.5wt%, 7wt%, 7.5wt%, 8wt%, etc. and any range between two point values.

[0047] In some preferred embodiments of the present application, the surface improvement aid includes vinyl MQ silicone resin. Further preferably, the average molecular weight of the vinyl MQ silicone resin is 6000-8000 g / mol, which is more conducive to improving the surface dryness and thereby improving the moisture-proof, salt-fog-proof and mildew-proof performance.

[0048] In some preferred embodiments of the present application, the surface improvement aid includes polymethyl methacrylate. Further preferably, the average molecular weight of the polymethyl methacrylate is 10000-50000 g / mol, which is more conducive to improving the surface dryness and thereby improving the moisture-proof, salt-fog-proof and mildew-proof performance.

[0049] Since the high molecular weight of the surface improvement aid increases the viscosity of the three-proofing paint, affects the elasticity of the cured oligomer, and affects the surface oxygen inhibition level, the application requires that the molecular weight of the surface improvement aid be within the above respective suitable ranges, which is more conducive to reducing the elasticity of the cured oligomer and reducing the surface oxygen inhibition level.

[0050] Further preferably, the amount of the vinyl MQ silicone resin accounts for 0.5wt%-3wt% based on the total amount of raw materials.

[0051] Further preferably, the amount of the polymethyl methacrylate accounts for 2wt%-8wt% based on the total amount of raw materials.

[0052] Preferably, the ratio of the average molecular weight of the oligomer to the polymethyl methacrylate is 1:(0.67-16.67), which is more conducive to adjusting the proportion of the polymethyl methacrylate according to the molecular weight of the oligomer to improve the surface dryness, thereby improving the moisture resistance, salt mist resistance, and mildew resistance.

[0053] Preferably, the mass ratio of the oligomer to the reaction monomer is 1:(0.67-4.33), more preferably 1:(0.67-3.00), and further preferably 1:(0.67-1.50), which is more conducive to adjusting the viscosity of the product and effectively improving the oxygen inhibition phenomenon, thereby improving the moisture resistance, salt mist resistance, and mildew resistance.

[0054] In the application, the reaction monomer refers to a small molecular compound capable of participating in polymerization. According to the number of functional groups capable of participating in polymerization contained in the reaction monomer molecule, the reaction monomer can be classified into monofunctional reaction monomer, bifunctional reaction monomer, trifunctional reaction monomer, etc. In the application, the functional group participating in polymerization is an acrylic acid group, which is classified according to the number of acrylic acid groups in the reaction monomer. In some preferred embodiments of the application, the reaction monomer includes at least one of monofunctional reaction monomer, bifunctional reaction monomer, and trifunctional reaction monomer.

[0055] Further preferably, the amount of the monofunctional reaction monomer accounts for 0wt%-65wt%, the amount of the bifunctional reaction monomer accounts for 0wt%-65wt%, and the amount of the trifunctional reaction monomer accounts for 0wt%-65wt% based on the total amount of raw materials, and the amounts of the monofunctional reaction monomer, the bifunctional reaction monomer, and the trifunctional reaction monomer are not zero at the same time. In the application, one reaction monomer can be added alone, or multiple different reaction monomers can be added at the same time.

[0056] In some preferred embodiments of the application, the total amount of the reaction monomer accounts for 30wt%-65wt% based on the total amount of raw materials, which is more conducive to diluting the oligomer and effectively improving the oxygen inhibition phenomenon, thereby improving the moisture resistance, salt mist resistance, and mildew resistance.

[0057] In some preferred embodiments of the present application, the monofunctional reactive monomer includes at least one of isobornyl acrylate (i.e. IBOA), dicyclopentenyl acrylate (i.e. DCPA), lauryl acrylate (i.e. LA), butyl acrylate, 2-ethylhexyl acrylate, isooctyl acrylate.

[0058] Further preferably, the monofunctional reactive monomer includes dicyclopentenyl acrylate, which is more conducive to improving the moisture resistance, salt mist resistance and mildew resistance.

[0059] Preferably, the difunctional reactive monomer includes 1,6-hexanediol diacrylate (i.e. HDDA) and / or tricyclodecane dimethanol diacrylate (i.e. DCPDA).

[0060] Preferably, the trifunctional reactive monomer includes trimethylolpropane triacrylate (i.e. TMPTA).

[0061] In some preferred embodiments of the present application, when the water vapor transmission rate of the three-proofing coating after being coated to a thickness of 50 μm under the condition of 38℃, 90% RH is below 15 g / (m 2 ·24h), the reactive monomer includes at least one of isobornyl acrylate, dicyclopentenyl acrylate, and tricyclodecane dimethanol diacrylate.

[0062] Preferably, when the water vapor transmission rate of the three-proofing coating after being coated to a thickness of 50 μm under the condition of 38℃, 90% RH is greater than 15 g / (m 2 ·24h), the reactive monomer includes butyl acrylate and / or 2-ethylhexyl acrylate.

[0063] For three-proofing coatings with different water vapor transmission rate requirements, the present application uses the above different suitable types of reactive monomers, which is more conducive to reducing costs according to requirements, while effectively improving the oxygen inhibition phenomenon, thereby improving the moisture resistance, salt mist resistance and mildew resistance.

[0064] Due to the inevitable oxygen inhibition problem in UV curing, selecting a suitable photoinitiator and adding amount can effectively reduce the oxygen inhibition of the three-proofing coating. In some preferred embodiments of the present application, the raw material of the three-proofing coating further includes a photoinitiator, and the mass ratio of the oligomer to the photoinitiator is 1: (0.05-2.67), which is more conducive to effectively reducing the oxygen inhibition of the three-proofing coating. The photoinitiator can be any photoinitiator in the prior art, for example, can include at least one of photoinitiator 184, photoinitiator 907, photoinitiator 379, photoinitiator 819, etc.

[0065] Further preferably, the amount of the photoinitiator is 3wt%-10wt%.

[0066] In some preferred embodiments of the present application, the raw materials of the tri-proof coating further comprise at least one of a polymerization inhibitor, an adhesion promoter, and a fluorescent whitening agent. The polymerization inhibitor, the adhesion promoter, and the fluorescent whitening agent can be any corresponding polymerization inhibitor, adhesion promoter, and fluorescent whitening agent in the prior art, for example, the polymerization inhibitor can comprise at least one of 2,6-di-tert-butyl-p-cresol (BHT), Rianlon 9788, etc., the adhesion promoter can comprise at least one of γ-(methacryloyloxy)propyltrimethoxysilane 174, alkyl acrylate phosphate, etc., and the fluorescent whitening agent can be UV-OB, for example.

[0067] Further preferably, the amount of the polymerization inhibitor is 0.01wt%-0.1wt%, the amount of the adhesion promoter is 0-1.5wt%, and the amount of the fluorescent whitening agent is 0.005wt%-0.05wt%, based on the total amount of the raw materials.

[0068] In the present application, the tri-proof coating can be UV-cured without adding other additives. In some preferred embodiments of the present application, when it is necessary to make the tri-proof coating undergo UV-humidity dual curing, the raw materials of the tri-proof coating further comprise at least one of methyl cyanoacrylate, butyl cyanoacrylate, acetic acid, and methacrylic acid, and the total amount of methyl cyanoacrylate and butyl cyanoacrylate is 0-3wt%, and the total amount of acetic acid and methacrylic acid is 0-0.1wt%, based on the total amount of the raw materials. The adoption of the scheme of additionally adding these additives is more conducive to curing, so that the coating is more complete after curing.

[0069] In a second aspect, the present application provides a preparation method of a tri-proof coating, which is used to prepare the tri-proof coating of the first aspect, and the preparation method comprises:

[0070] The reaction monomer comprising an acrylic group and the oligomer having an acrylic group-terminated and a polyisobutylene skeleton structure are mixed to obtain a first mixed solution;

[0071] The optional additive comprising at least one of a photoinitiator, a polymerization inhibitor, an adhesion promoter, and a fluorescent whitening agent is added to the first mixed solution to obtain a second mixed solution;

[0072] Then, a surface improvement additive is introduced to perform a third mixing.

[0073] In some preferred embodiments of the present application, the conditions of the first mixing comprise: the first mixing is performed in a planetary mixer at a rotation speed of 1800-2400 r / min for a mixing time of 100-200 s, and the first mixing is repeated for 1-5 times. The adoption of the first mixing process under suitable conditions is more conducive to the uniform mixing of the materials and improves the production efficiency.

[0074] In some preferred embodiments of the present application, the conditions of the second mixing include: being carried out in a planetary gear mixer, at a rotation speed of 1800-2400 r / min, for a mixing time of 100-200 s, and for 1-5 repetitions of the second mixing. The second mixing process under the appropriate conditions is more conducive to the uniform mixing of the materials, and improves the production efficiency.

[0075] In some preferred embodiments of the present application, the conditions of the third mixing include: being carried out in a planetary gear mixer, at a rotation speed of 1800-2400 r / min, for a mixing time of 100-200 s. The third mixing process under the appropriate conditions is more conducive to the uniform mixing of the materials, and improves the production efficiency.

[0076] In some preferred embodiments of the present application, when it is required to make the tri-proof coating to be UV and moisture dual-cured, the preparation method further comprises: introducing acetic acid and / or methacrylic acid into the third mixing liquid obtained from the third mixing to carry out a fourth mixing, and then introducing methyl cyanoacrylate and / or butyl cyanoacrylate to carry out a fifth mixing.

[0077] In some preferred embodiments of the present application, the conditions of the fourth and fifth mixings are each independently: being carried out in a planetary gear mixer, at a rotation speed of 1800-2400 r / min, for a mixing time of 100-200 s. The fourth and fifth mixing processes under the appropriate conditions are more conducive to the uniform mixing of the materials, and improve the production efficiency.

[0078] The following detailed description of the embodiments of the present application is exemplary and is only used to explain the present application, and cannot be understood as a limitation of the present application.

[0079] Example 1

[0080] The raw materials of the tri-proof coating are shown in Table 1, wherein the average molecular weight of the oligomer is 3000-15000 g / mol, and the dynamic viscosity at 25℃ is 1000000-3500000 cp. It is calculated that the mass ratio of the oligomer to the surface improvement aid is 1:0.03, and the mass ratio of the oligomer to the reaction monomer is 1:1.70.

[0081] Table 1

[0082]

[0083] The tri-proof coating is prepared according to the raw materials shown in Table 1 by the following preparation method:

[0084] IBOA is mixed with EPION TMEP400V was first mixed in a planetary gear mixer at 2000 r / min for 150 s, repeated 5 times to obtain a mixed solution 1, and the first mixing speed was 200 r / min. To the mixed solution 1, a photoinitiator 1607, a photoinitiator 184, a polymerization inhibitor BHT, and a fluorescent whitening agent UV-OB were added, and the obtained mixed solution was second mixed in a planetary gear mixer at 2100 r / min for 150 s, and after repeating the second mixing operation 4 times, a mixed solution 2 was obtained. A surface improvement aid, vinyl MQ silicone resin, was added to the mixed solution 2, and placed in a planetary gear mixer at 2000 r / min for mixing for 100 s, and the obtained mixed solution 3 was the target tri-proof coating.

[0085] Example 2

[0086] Refer to Example 1, the difference is that the type of surface improvement aid is adjusted to be replaced by polymethyl methacrylate, the average molecular weight of polymethyl methacrylate is 45000 g / mol, which is purchased from Mitsubishi Chemical Corporation in Japan, model BR-116, the amount of polymethyl methacrylate accounts for 5wt% of the total amount of raw materials, the content of other solutes except for the reaction monomer is unchanged, and the reaction monomer IBOA makes up the total amount of 100%. It is calculated that the average molecular weight ratio of the oligomer to the polymethyl methacrylate is 1:3, the mass ratio of the oligomer to the surface improvement aid is 1:0.15, and the mass ratio of the oligomer to the reaction monomer is 1:1.57.

[0087] Example 3

[0088] Refer to Example 1, the difference is that the following aids are also added: butyl cyanoacrylate 1wt% and acetic acid 0.01wt% based on the total amount of raw materials, the content of other solutes except for the reaction monomer is unchanged, and the reaction monomer IBOA makes up the total amount of 100%. And it also includes the following steps:

[0089] To the mixed solution 3, acetic acid was added and placed in a planetary gear mixer at 2000 r / min for mixing for 100 s to obtain a mixed solution 4. To the mixed solution 4, butyl cyanoacrylate was added and placed in a planetary gear mixer at 2000 r / min for mixing for 100 s to obtain a mixed solution 5, and the obtained mixed solution 5 was the target tri-proof coating.

[0090] Example 4

[0091] Refer to Example 1, the difference is that the amount of oligomer is different, which is specifically replaced by 20wt%, the content of other solutes except for the reaction monomer is unchanged, and the reaction monomer IBOA makes up the total amount of 100%. It is calculated that the mass ratio of the oligomer to the surface improvement aid is 1:0.05, and the mass ratio of the oligomer to the reaction monomer is 1:3.45.

[0092] Example 5

[0093] Example 1 was followed, except that the amount of surface improvement aid was adjusted so that the mass ratio of oligomer to surface improvement aid was 1:0.1. At this time, the amount of surface improvement aid accounted for 3.3wt% based on the total amount of raw materials, and the content of other solutes other than the reaction monomer was unchanged, and the reaction monomer IBOA made up the total amount of 100%. It was calculated that the mass ratio of oligomer to reaction monomer was 1:1.63.

[0094] Example 6

[0095] Example 1 was followed, except that the type of reaction monomer was adjusted and replaced with dicyclopentenyl acrylate (i.e., DCPA) without changing the amount.

[0096] Comparative Example 1

[0097] Example 1 was followed, except that the oligomer was replaced with a polymer with an acrylate group terminated non-polyisobutylene skeleton structure, specifically a polyurethane skeleton, without changing the amount. And the dynamic viscosity of the oligomer at 25°C was 13000cp, purchased from Guangdong Hao Hui New Material Co., Ltd., model CR93110.

[0098] Comparative Example 2

[0099] Example 1 was followed, except that no surface improvement aid was added.

[0100] Comparative Example 3

[0101] Example 1 was followed, except that the amount of surface improvement aid was adjusted so that the mass ratio of oligomer to surface improvement aid was 1:0.005.

[0102] Comparative Example 4

[0103] Example 1 was followed, except that the amount of surface improvement aid was adjusted so that the mass ratio of oligomer to surface improvement aid was 1:0.7.

[0104] Test Example

[0105] The performance of the three-proofing coatings obtained in the above examples and comparative examples was tested, and the results are shown in Table 3. The water vapor transmission amount of the obtained three-proofing coatings after coating to a thickness of 50μm was tested according to GB / T 1037-2021 at 38°C, 90%RH, and the results are shown in Table 3, with the unit of g / (m 2 ·24h), and the water vapor transmission rate coefficient was tested by GB / T 1037-2021 using a constant temperature and humidity chamber for final calculation.

[0106] The test method of oxygen inhibition index is as follows: the three-proofing paint sample is placed on a release film, a wet film coater is used to prepare a 50 micrometer thick wet film of the three-proofing paint, the three-proofing paint and the release film are placed in a UV curing oven for curing for 20 seconds, the cured three-proofing paint dry film and the release film are made into a circular film with a diameter of 65 millimeters by using a hydraulic press, and the obtained circular film is the sample; the sample is tested by the following steps: (1) the mass of the sample is weighed by using an electronic balance, and W0 is recorded; (2) the sample is irradiated by using a UV lamp, and the integrity of the sample is checked; (3) a standard sieve is placed directly above the sample, 5 grams of talcum powder is weighed, and the talcum powder is evenly distributed above the sample; (4) the standard sieve is slightly collided to make the talcum powder evenly fall on the surface of the sample, and the coverage integrity is checked by using a UV lamp; (5) one end of the sample is clamped by using tweezers, and the sample is vertically 90 degrees, so that the surface talcum powder falls off; (6) the sample is placed flat again, and is vertically 90 degrees again, and the mass of the sample is weighed by using an electronic balance after repeating 5 times, and W1 is recorded; (7) the mass difference before and after the sample (i.e. the difference between W0 and W1) is calculated, and the oxygen inhibition level is compared according to the grade division in Table 2. According to the above oxygen inhibition test standard, the mass difference before and after the sample of each comparative example and the oxygen inhibition level are as shown in Table 3 (three samples are prepared for each test, and the average value is taken). The smaller the mass difference before and after the sample, the lower the surface viscosity, and the less the oxygen inhibition phenomenon, which is more beneficial to the performance of the three-proofing paint.

[0107] Table 2

[0108]

[0109] Table 3

[0110]

[0111] It can be known from the above results that, compared with the comparative examples, the three-proofing paint has low water vapor transmission rate and extremely low oxygen inhibition, and has good moisture-proof, salt mist-proof and mildew-proof performance, which is beneficial to the protection of the circuit board.

[0112] Further, according to examples 1 and 2-5, the preferred scheme of the present application is more beneficial to obtaining low water vapor transmission rate, extremely low oxygen inhibition, and improving the three-proofing performance, which provides a good choice for the protection of the circuit board. The effect of example 1 of the present application using vinyl MQ silicone resin is better than that of example 2 using polymethyl methacrylate.

[0113] Compared with example 1, example 3 of the present application further adds butyl cyanoacrylate additive, the butyl cyanoacrylate on the surface of the sample is cured by moisture, which makes up for the disadvantage of oxygen inhibition; but the water vapor transmission amount is relatively high.

[0114] Compared with Example 1, the oligomer addition amount of Example 4 of the application is small, the acrylic monomer is more, and the surface oxygen inhibition is less.

[0115] Compared with Example 1, the addition of more vinyl MQ silicone resin in Example 5 of the application can further slow down the oxygen inhibition.

[0116] The oligomer of Comparative Example 1 is replaced by other structural polyurethane acrylate with lower molecular weight, and its oxygen inhibition is slightly better than that of Example 1, but its water vapor transmission rate is too high.

[0117] Comparative Example 2 does not add vinyl MQ silicone resin, and Comparative Example 3 adds a small amount of vinyl MQ silicone resin, and the amount does not meet the mass ratio with the specific oligomer of the application, and the surface oxygen inhibition is obvious.

[0118] The above describes the preferred embodiments of the application in detail, but the application is not limited thereto. Within the technical concept of the application, various simple modifications can be made to the technical solutions of the application, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be considered as disclosed by the application and belong to the protection scope of the application.

Claims

1. A three-protective coating characterized by, The raw materials include: a reaction monomer containing an acrylic group, a surface improvement aid, and an oligomer; and the amount of the oligomer is 15 wt% to 45 wt% based on the total amount of the raw materials, and the mass ratio of the oligomer to the surface improvement aid is 1:(0.011-0.533); wherein the oligomer has the following general formula: n=40-250； The surface improvement aid includes a vinyl MQ silicone resin, the average molecular weight of the vinyl MQ silicone resin is 6000-8000 g / mol, and the amount of the vinyl MQ silicone resin is 0.5 wt% to 3 wt% based on the total amount of the raw materials.

2. The paint according to claim 1, wherein The average molecular weight of the oligomer is 3000-15000 g / mol and the dynamic viscosity at 25℃ is 1000000-3500000 cp.

3. The paint according to claim 1, wherein The total amount of the reaction monomer is 30 wt% to 65 wt% based on the total amount of the raw materials, and / or the mass ratio of the oligomer to the reaction monomer is 1:(0.67-4.33).

4. The paint according to claim 1, wherein The reaction monomer includes at least one of a monofunctional reaction monomer, a bifunctional reaction monomer, and a trifunctional reaction monomer, the amount of the monofunctional reaction monomer is 0 wt% to 65 wt% based on the total amount of the raw materials, the amount of the bifunctional reaction monomer is 0 wt% to 65 wt%, and the amount of the trifunctional reaction monomer is 0 wt% to 65 wt%, and the amounts of the monofunctional reaction monomer, the bifunctional reaction monomer, and the trifunctional reaction monomer are not all zero at the same time.

5. The paint according to claim 4, wherein The monofunctional reaction monomer includes at least one of isobornyl acrylate, dicyclopentenyl acrylate, lauryl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and isooctyl acrylate; the bifunctional reaction monomer includes 1,6-hexanediol diacrylate and / or tricyclodecane dimethanol diacrylate; and the trifunctional reaction monomer includes trimethylolpropane triacrylate.

6. The paint for preventing water, dust and chemicals according to claim 4 or 5, wherein The monofunctional reaction monomer includes dicyclopentenyl acrylate.

7. The paint according to claim 1, wherein The raw materials of the three-proofing coating further include a photoinitiator, The mass ratio of the oligomer to the photoinitiator is 1:(0.05-2.67); and / or the amount of the photoinitiator is 3 wt% to 10 wt%.

8. The paint according to claim 1, wherein The raw materials of the three-proofing coating further include at least one of a polymerization inhibitor, an adhesion promoter, and a fluorescent whitening agent, the amount of the polymerization inhibitor is 0.01 wt% to 0.1 wt% based on the total amount of the raw materials, the amount of the adhesion promoter is 0-1.5 wt%, and the amount of the fluorescent whitening agent is 0.005 wt% to 0.05 wt%.

9. The paint according to claim 1, wherein When it is necessary to make the three-proofing coating perform UV and moisture dual curing, the raw materials of the three-proofing coating further include at least one of a cyan acrylate, butyl cyanoacrylate, acetic acid, and methacrylic acid, the total amount of the cyan acrylate and the butyl cyanoacrylate is 0-3 wt% based on the total amount of the raw materials, and the total amount of the acetic acid and the methacrylic acid is 0-0.1 wt%.

10. A method for producing a three-protective coating, characterized by, It is used for preparing the three-proofing coating as claimed in any one of claims 1-9, and the preparation method includes: The reaction monomer containing an acrylic group and the oligomer with an acrylic group end-capped and a polyisobutylene skeleton structure are first mixed to obtain a first mixed solution; The first mixed solution is mixed with a surface improvement aid to obtain a second mixed solution; The optional auxiliary agent including at least one of a photoinitiator, a polymerization inhibitor, an adhesion promoter, a fluorescent whitening agent is added to the first mixed solution, and second mixing is performed to obtain a second mixed solution; Then, a surface improvement auxiliary agent is introduced for third mixing.

11. The production method of the three-layered paint according to claim 10, wherein The first mixing conditions include: being performed in a planetary mixer at a rotation speed of 1800-2400 r / min, a mixing time of 100-200 s, and a repetition number of 1-5 times; The second mixing conditions include: being performed in a planetary gear mixer at a rotation speed of 1800-2400 r / min, a mixing time of 100-200 s, and a repetition number of 1-5 times; The third mixing conditions include: being performed in a planetary gear mixer at a rotation speed of 1800-2400 r / min, a mixing time of 100-200 s.

12. The production method of the three-layered paint according to claim 10, wherein When it is required to make the three-proofing paint perform UV and moisture dual curing, the preparation method further includes: introducing acetic acid and / or methacrylic acid into the third mixed solution obtained by the third mixing for fourth mixing, and then introducing methyl cyanoacrylate and / or butyl cyanoacrylate for fifth mixing; The fourth mixing and the fifth mixing each independently include: being performed in a planetary gear mixer at a rotation speed of 1800-2400 r / min, a mixing time of 100-200 s.

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