UV moisture curing conformal coating composition with low odor after curing and preparation method thereof

Abstract

The invention discloses a UV moisture-cured three-proofing paint composition with low odor after curing and a preparation method of the UV moisture-cured three-proofing paint composition. The cured low-odor UV moisture curing three-proofing paint composition is prepared from the following components in parts by mass: 50 to 70 parts of bifunctional aliphatic urethane acrylate resin, 10 to 30 parts of cyclic trimethylolpropane formal acrylate, 10 to 30 parts of isobornyl methacrylate and 5 to 10 parts of a photoinitiator. According to the application, low-odor monomers such as cyclic trimethylolpropane formal acrylate and isobornyl methacrylate are added to replace irritant monomers, so that the problem of strong odor of the conformal coating is greatly reduced; by adding the macromolecular photoinitiator, the problem that the residual initiator on the paint film volatilizes due to heating to generate odor is solved, and the problem that the odor volatilizes due to the influence of temperature even if the residual initiator exists due to the fact that the photoinitiator is macromolecular is solved.

Description

Technical Field

[0001] This application relates to the field of polymer materials, and in particular to a UV moisture-curing conformal coating composition with low odor after curing and its preparation method. Background Technology

[0002] Currently, commonly used UV moisture-curing conformal coatings usually have a strong odor, and the odor remains after curing. For PCB conformal adhesives used in rice cookers, water dispensers, washing machines, etc., the commonly used conformal adhesives have a strong monomer odor and initiator residue. After the coating film is cured, when heated, the small molecules in the coating film and the residual initiator will volatilize, causing an odor to be generated when the appliance is used.

[0003] Therefore, developing a conformal coating that can maintain low odor after curing is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] In view of this, this application provides a UV moisture-curing conformal coating composition with low odor after curing, which is less susceptible to odor problems caused by temperature fluctuations when applied to PCB electrical boards.

[0005] This application provides a UV moisture-curing conformal coating composition with low odor after curing, comprising, by weight parts: 50 to 70 parts of difunctional aliphatic urethane acrylate resin, 10 to 30 parts of cyclic trimethylolpropane formal acrylate, 10 to 30 parts of isobornyl methacrylate and 5 to 10 parts of photoinitiator.

[0006] In some specific implementations, the components, by weight, include: 50 to 65 parts of dihydroxyaliphatic urethane acrylate resin, 15 to 20 parts of cyclic trimethylolpropane formaldehyde acrylate, 15 to 25 parts of isobornyl methacrylate, and 5 to 10 parts of photoinitiator.

[0007] In some specific implementations, the difunctional aliphatic urethane acrylate resin includes CR93110 and / or CR91410.

[0008] In some specific implementations, the photoinitiator includes D-806.

[0009] In some specific implementations, the cured low-odor UV moisture-curing conformal coating composition further includes, by weight parts: 0.1 to 1 part desiccant, 0.03 to 0.1 part fluorescent whitening agent, 0.5 to 1 part leveling agent, and 0.2 to 0.5 parts defoamer.

[0010] In some specific implementations, the cured low-odor UV moisture-curing conformal coating composition further includes, by weight parts: 0.1 to 0.5 parts of desiccant, 0.03 to 0.1 parts of fluorescent whitening agent, 0.5 to 1 part of leveling agent, and 0.2 to 0.5 parts of defoamer.

[0011] In some specific implementations, the dehydrating agent comprises a low-viscosity isocyanate, and the fluorescent whitening agent comprises 2,5-bis(5-tert-butyl-2-benzoxazolyl)thiophene.

[0012] In some specific implementations, the leveling agent includes BYK333, and the defoamer includes TEGO920.

[0013] This application also provides a method for preparing a low-odor UV moisture-cured conformal coating after curing, comprising:

[0014] A mixture of difunctional aliphatic urethane acrylate resin, cyclic trimethylolpropane formaldehyde acrylate, isoborneol methacrylate and photoinitiator is used to obtain a UV moisture-curing conformal coating composition with low odor after curing.

[0015] The UV moisture-curing conformal coating composition with low odor after curing was cured to obtain a UV moisture-curing conformal coating with low odor after curing.

[0016] In some specific implementations, the curing process includes ultraviolet radiation and moisture curing, wherein the energy of the ultraviolet radiation is 1000 mJ / cm². 2 Up to 2000mj / cm 2 After curing, the product is placed indoors and allowed to undergo moisture curing in the air for 60 to 100 hours.

[0017] This application also provides a UV moisture-curing conformal coating with low odor after curing, which is prepared according to the preparation method described above.

[0018] This application significantly reduces the strong odor of conformal paint by adding low-odor monomers such as cyclic trimethylolpropane acetal acrylate and isoborneol methacrylate to replace irritating monomers. Furthermore, by adding the macromolecular photoinitiator D-806 to replace commonly used photoinitiators such as MBF, 1173, and 184, the problem of odor caused by the volatilization of residual initiators on the paint film due to heat is solved. Since the photoinitiator is a macromolecule, even if there are residual initiators, they are not easily affected by temperature to volatilize and emit odors. Detailed Implementation

[0019] It should be understood that the expression “one or more of…” individually includes each of the objects described after the expression, as well as various different combinations of two or more of the described objects, unless otherwise understood from the context and usage. The expression “and / or” combined with three or more described objects should be understood to have the same meaning, unless otherwise understood from the context.

[0020] The terms “including,” “having,” or “containing,” including the use of their grammatical synonyms, should generally be understood as open-ended and non-restrictive, for example, not excluding other unstated elements or steps, unless otherwise specifically stated or understood from the context.

[0021] It should be understood that the order of steps or the sequence of actions is not important as long as this application remains operational. Furthermore, two or more steps or actions can be performed simultaneously.

[0022] The use of any and all instances or exemplary language such as “e.g.” or “include” in this document is intended merely to better illustrate the application and does not constitute a limitation on the scope of the application. No language in this specification should be construed as indicating that any unclaimed element is essential to the practice of this application.

[0023] Furthermore, the numerical ranges and parameters used to define this application are approximate values, and the relevant values ​​in the specific embodiments have been presented as precisely as possible. However, any numerical value inevitably contains standard deviations due to individual test methods. Therefore, unless otherwise explicitly stated, it should be understood that all ranges, quantities, values, and percentages used in this disclosure are modified with the word "approximately." Here, "approximately" generally means that the actual value is within plus or minus 10%, 5%, 1%, or 0.5% of a specific value or range.

[0024] This application provides a UV moisture-curing conformal coating composition with low odor after curing, comprising, by weight parts: 50 to 70 parts of difunctional aliphatic urethane acrylate resin, 10 to 30 parts of cyclic trimethylolpropane formal acrylate, 10 to 30 parts of isobornyl methacrylate and 5 to 10 parts of photoinitiator.

[0025] The cured low-odor UV moisture-curing conformal coating composition comprises a difunctional aliphatic urethane acrylate resin. In some specific implementations, the difunctional aliphatic urethane acrylate resin includes CR93110 and CR91410 from Guangdong Haohui Company, one of which serves as the main film-forming substance, and the other is a polyurethane acrylate resin containing both acryloyl and isocyanate functional groups, enabling dual curing methods of free radical curing and moisture curing. The mass fraction of the difunctional aliphatic urethane acrylate resin is 50 to 70 parts, specifically 50, 52, 54, 55, 56, 58, 60, 62, 64, 66, 68, or 70 parts.

[0026] The low-odor UV moisture-curing conformal coating composition after curing includes cyclic trimethylolpropane formal acrylate (CTFA). CTFA has low odor, fast curing speed, and good flexibility, and can replace the commonly used monomer THFA, which has a strong odor problem, thus improving the odor issue. The mass fraction of CTFA is from 10 to 30 parts, specifically 10, 12, 14, 15, 18, 20, 22, 24, 26, 28, or 30 parts.

[0027] The cured low-odor UV moisture-curing conformal coating composition includes isoborneol methacrylate. In some specific implementations, the isoborneol methacrylate includes, but is not limited to, IBOMA from Changxing Materials Industry Co., Ltd., which has low odor, good adhesion, and contains multiple methyl groups. Compared to IBOMA, it has a larger molecular weight and a much lower odor than the volatile odor of IBOMA. The mass fraction of the isoborneol methacrylate is from 10 to 30 parts, specifically 10, 12, 14, 15, 18, 20, 22, 24, 26, 28, or 30 parts.

[0028] The low-odor UV moisture-curing conformal coating composition after curing includes a photoinitiator. In some specific implementations, the photoinitiator includes, but is not limited to, D-806, specifically the D-806 photoinitiator from Laitecore New Materials. This is a solid macromolecular initiator. Compared to commonly used initiators such as MBF, 184, and 1173, the D-806 macromolecular initiator does not volatilize upon heating after curing, thus reducing the odor problem of the coating film. The photoinitiator is present in quantities of 5 to 10 parts by weight, specifically 5, 6, 7, 8, 9, or 10 parts.

[0029] In some specific implementations, the components, by weight, include: 50 to 65 parts of dihydroxyaliphatic urethane acrylate resin, 15 to 20 parts of cyclic trimethylolpropane formaldehyde acrylate, 15 to 25 parts of isobornyl methacrylate, and 5 to 10 parts of photoinitiator.

[0030] The cured low-odor UV moisture-curing conformal coating composition includes a desiccant. In some specific implementations, the desiccant includes a low-viscosity isocyanate. This is a highly reactive, low-viscosity isocyanate widely used in polyurethane coatings, effectively removing moisture and improving the stability and performance of the coating. The desiccant is present in parts by weight from 0.1 to 1 part, specifically 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or 1 part.

[0031] The cured low-odor UV moisture-curing conformal coating composition includes a fluorescent whitening agent. In some specific implementations, the fluorescent whitening agent includes, but is not limited to, 2,5-bis(5-tert-butyl-2-benzoxazolyl)thiophene. The fluorescent whitening agent is present in amounts from 0.03 parts to 0.1 parts by weight, specifically 0.03 parts, 0.04 parts, 0.05 parts, 0.06 parts, 0.07 parts, 0.08 parts, 0.09 parts, or 0.1 parts.

[0032] The cured low-odor UV moisture-curing conformal coating composition includes a leveling agent, which in some specific implementations includes, but is not limited to, BYK333. The leveling agent is present in parts by weight from 0.5 to 1 part, and can be 0.5, 0.6, 0.7, 0.8, 0.9, or 1 part.

[0033] The cured low-odor UV moisture-curing conformal coating composition includes a defoamer. In some specific implementations, the defoamer includes, but is not limited to, TEGO920. The defoamer is present in parts by weight of 0.2 to 0.5 parts, specifically 0.2, 0.3, 0.4, or 0.5 parts.

[0034] In some specific implementations, the cured low-odor UV moisture-curing conformal coating composition further includes, by weight parts: 0.1 to 0.5 parts of desiccant, 0.03 to 0.1 parts of fluorescent whitening agent, 0.5 to 1 part of leveling agent, and 0.2 to 0.5 parts of defoamer.

[0035] This application also provides a method for preparing a low-odor UV moisture-cured conformal coating after curing, comprising:

[0036] A mixture of difunctional aliphatic urethane acrylate resin, cyclic trimethylolpropane formaldehyde acrylate, isoborneol methacrylate and photoinitiator is used to obtain a UV moisture-curing conformal coating composition with low odor after curing.

[0037] The UV moisture-curing conformal coating composition with low odor after curing was cured to obtain a UV moisture-curing conformal coating with low odor after curing.

[0038] In some specific implementations, the curing process includes ultraviolet radiation and moisture curing, wherein the energy of the ultraviolet radiation is 1000 mJ / cm². 2 Up to 2000mj / cm 2 After curing, the product is placed indoors and allowed to undergo moisture curing in the air for 60 to 100 hours.

[0039] When using the low-odor UV moisture-curing conformal coating composition of this application for coating, the following conditions should be met: Material: PCB circuit board; UV radiation curing conditions: Mercury lamp type: UV; Mercury lamp output power: 2000W; Curing energy: 1000-2000mj / cm² 2 PCB → Spray coating → 80-150 microns → UV curing → 1000-2000 mj / cm 2 →Let stand for 72 hours. Spray 80-150 micrometer coating onto the PCB board, then cure with a mercury lamp at an energy of 1000-2000 mJ / cm². 2 It needs to be left to cure the moisture for 72 hours before use.

[0040] This application also provides a UV moisture-curing conformal coating with low odor after curing, which is prepared according to the preparation method described above.

[0041] The present application is further illustrated below with reference to embodiments. The scope of protection of the present application is not limited to the following embodiments.

[0042] Example 1

[0043] This embodiment provides a low-odor UV moisture-cured conformal coating after curing, the composition of which is shown in Table 1. The preparation method of the low-odor UV moisture-cured conformal coating after curing includes:

[0044] Step 1: Add 15 parts CTFA, 25 parts IBOMA, 0.03 parts fluorescent whitening agent OB, 5 parts photoinitiator D-806 and 0.1 parts dehydrating agent TI to the reactor in sequence; after purging with nitrogen to remove air, seal and stir at 800~1000 rpm for 30 to 60 minutes to ensure that all components are fully dispersed.

[0045] Step 2: Add 50 parts of difunctional aliphatic urethane acrylate resin CR93110, 0.5 parts of leveling agent BYK333, and 0.2 parts of defoamer TEGO920 to the mixture obtained in Step 1, and disperse at 800~1000 rpm for 1-2 hours to ensure that the components are fully dispersed.

[0046] Step 3: Allow the mixture obtained in Step 2 to stand to remove air bubbles or remove air bubbles under vacuum, then filter it with a 300-mesh filter cloth. When packaging, nitrogen gas should be used to protect the packaging and prevent it from coming into contact with moisture in the air.

[0047] When using the low-odor UV moisture-curing conformal coating of this application for coating, the following conditions shall be met:

[0048] Material: PCB circuit board; UV curing conditions: Mercury lamp type: UV. Mercury lamp output power: 2000W, curing energy: 1000-2000mj / cm² 2 PCB → Spray coating → 80-150 microns → UV curing → 1000-2000 mj / cm 2 →Let stand for 72 hours. Spray 80-150 micrometer coating onto the PCB board, then cure with a mercury lamp at an energy of 1000-2000 mJ / cm². 2 It needs to be left to cure the moisture for 72 hours before use.

[0049] Example 2

[0050] This embodiment provides a UV moisture-curing conformal coating with low odor after curing. Its composition is shown in Table 1. The preparation method of the UV moisture-curing conformal coating with low odor after curing differs from that of Example 1 only in that: IBOMA is 27 parts, CR93110 is 57 parts, CTFA is 11 parts, D-806 is 6 parts, OB is 0.05 parts, TI is 0.2 parts, BYK333 is 0.7 parts, TEGO920 is 0.3 parts, and the test performance remains unchanged.

[0051] Example 3

[0052] This embodiment provides a UV moisture-curing conformal coating with low odor after curing. Its composition is shown in Table 1. The preparation method of the UV moisture-curing conformal coating with low odor after curing differs from that of Example 1 only in that: IBOMA is 24 parts, CR93110 is 60 parts, CTFA is 13 parts, D-806 is 7 parts, OB is 0.07 parts, TI is 0.3 parts, BYK333 is 0.8 parts, TEGO920 is 0.3 parts, and the test performance remains unchanged.

[0053] Example 4

[0054] This embodiment provides a UV moisture-curing conformal coating with low odor after curing. Its composition is shown in Table 1. The preparation method of the UV moisture-curing conformal coating with low odor after curing differs from that of Example 1 only in that: IBOMA is 22 parts, CR93110 is 63 parts, CTFA is 14 parts, D-806 is 8 parts, OB is 0.05 parts, TI is 0.3 parts, BYK333 is 0.9 parts, TEGO920 is 0.4 parts, and the test performance remains unchanged.

[0055] Example 5

[0056] This embodiment provides a UV moisture-curing conformal coating with low odor after curing. Its composition is shown in Table 1. The preparation method of the UV moisture-curing conformal coating with low odor after curing differs from that of Example 1 only in that: IBOMA is 20 parts, CR93110 is 65 parts, CTFA is 15 parts, D-806 is 10 parts, OB is 0.1 parts, TI is 0.4 parts, BYK333 is 1 part, and TEGO920 is 0.5 parts, and the test performance remains unchanged.

[0057] Comparative Example 1

[0058] This comparative example provides a UV moisture-cured conformal coating with low odor after curing. Its composition is shown in Table 1. The preparation method of the UV moisture-cured conformal coating with low odor after curing differs from that of Example 1 only in that the amount of monomer CTFA added is changed to 0 parts, while the other added amounts remain unchanged. The test performance changes, the reaction becomes slower, the adhesion becomes worse, the coating film surface becomes sticky, and some monomers fail to crosslink completely. During heating and baking, a strong interfering odor is generated.

[0059] Comparative Example 2

[0060] This comparative example provides a UV moisture-cured conformal coating with low odor after curing. Its composition is shown in Table 1. The preparation method of the UV moisture-cured conformal coating with low odor after curing differs from that of Example 1 only in that: when the amount of monomer CTFA added is 0 parts, the other added amounts remain unchanged, the test performance changes, the adhesion becomes worse, and although no odor is generated, the adhesion is only 2B.

[0061] Table 1

[0062]

[0063] The test methods for the low-odor UV moisture-cured conformal coatings provided in Examples 1-5 and Comparative Examples 1 and 2 after curing are as follows:

[0064] Adhesion: GB / T 1720-1979(1989) Test for adhesion of paint films using cross-cut adhesion tester;

[0065] Surface dry: The touch test involves lightly touching the surface of the paint film with your finger. If it feels slightly sticky but not sticky to your finger, and no paint sticks to your finger, it is considered surface dry.

[0066] Odor of refined oil products: Odor level determination method;

[0067] Odor of cured paint film: Odor level determination method;

[0068] High temperature and high humidity: Reliability testing was conducted at 85℃ and 85% relative humidity.

[0069] Salt spray: Reliability test conducted in an environment of 5% sodium chloride neutral solution, 35℃±2℃, pH 6.5~7.2.

[0070] The odor intensity levels are shown in Table 2.

[0071] Table 2

[0072]

[0073] The test results are shown in Table 3.

[0074] Table 3

[0075]

[0076] The above description is merely a preferred embodiment of this application, but the scope of protection of this application is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in this application, based on the technical solution and application concept of this application, should be included within the scope of protection of this application.

Claims

1. A UV moisture-curable undercoating paint composition having low odor after curing, characterized by, The low-odor UV moisture-cured three-protection paint composition after curing comprises, in mass fraction: 50-70 parts of a diurethane aliphatic acrylate resin, 10-30 parts of a cyclic trimethylolpropane formal acrylate, 10-30 parts of isobornyl methacrylate, and 5-10 parts of a photoinitiator.

2. The low-odor, UV-humidity cured, penta-coat paint composition after curing according to claim 1, characterized in that, The low-odor UV moisture-cured three-protection paint composition after curing comprises, in mass fraction: 50-70 parts of a diurethane aliphatic acrylate resin, 10-30 parts of a cyclic trimethylolpropane formal acrylate, 10-30 parts of isobornyl methacrylate, and 5-10 parts of a photoinitiator.

3. The low-odor, UV-humidity cured, penta-coat paint composition after curing according to claim 1, characterized in that, The diurethane aliphatic acrylate resin comprises CR93110 and / or CR91410.

4. The low-odor, UV-humidity cured, penta-coat paint composition according to claim 1, wherein, The photoinitiator comprises D-806.

5. The low-odor, UV-humidity cured, pentaerythritol-based, three-part, penta- functional, moisture-cured polyurethane coating composition of claim 1, wherein, The low-odor UV moisture-cured three-protection paint composition after curing further comprises, in mass fraction: 0.1-1 part of a water-removing agent, 0.03-0.1 part of a fluorescent whitening agent, 0.5-1 part of a leveling agent, and 0.2-0.5 part of an antifoaming agent.

6. The low-odor, UV-humidity cured, penta-coat paint composition according to claim 1, wherein, The low-odor UV moisture-cured three-protection paint composition after curing further comprises, in mass fraction: 0.1-0.5 part of a water-removing agent, 0.03-0.1 part of a fluorescent whitening agent, 0.5-1 part of a leveling agent, and 0.2-0.5 part of an antifoaming agent.

7. The low-odor, UV-humidity cured, penta-coat paint composition according to claim 5, wherein, The water-removing agent comprises a low-viscosity isocyanate, the fluorescent whitening agent comprises 2,5-bis(5-tert-butyl-2-benzoxazolyl)thiophene, the leveling agent comprises BYK333, and the antifoaming agent comprises TEGO920.

8. A method for producing a UV moisture-curable undercoating paint having low odor after curing, characterized by, The low-odor UV moisture-cured three-protection paint composition after curing comprises, in mass fraction: 50-70 parts of a diurethane aliphatic acrylate resin, 10-30 parts of a cyclic trimethylolpropane formal acrylate, 10-30 parts of isobornyl methacrylate, and 5-10 parts of a photoinitiator. The low-odor UV moisture-cured three-protection paint composition after curing comprises, in mass fraction: 50-70 parts of a diurethane aliphatic acrylate resin, 10-30 parts of a cyclic trimethylolpropane formal acrylate, 10-30 parts of isobornyl methacrylate, and 5-10 parts of a photoinitiator. The low-odor UV moisture-cured three-protection paint composition after curing is prepared according to the preparation method of claim 8 or 9.

9. The production method according to claim 8, characterized by, The curing comprises a first UV radiation with an energy of 1000 mj / cm 2 up to 2000 mj / cm 2 and a subsequent moisture curing with air moisture for a time of 60 h to 100 h.

10. A UV moisture-cured undercoating paint with low odor after curing, characterized by, ​

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