UV / moisture dual-curing composition as well as preparation method and application thereof

Abstract

The invention discloses a UV / moisture dual-curing organic silicon resin composition and a preparation method thereof. The composition comprises the following components: (A) 85-96 wt% of acrylic modified silicone resin; (B) 0.5-2 wt% of a photoinitiator; (C) an acrylic ester diluent with the content of 1 to 5 weight percent; (D) 0.5-2 wt% of an organic metal catalyst; (E) 1-5 wt% of polyether modified silicone oil; and (F) 0.02-1 wt% of an auxiliary agent. The composition has the characteristics of good storage stability, deep curing depth, low light curing energy, high curing efficiency, good protection performance and the like.

Description

Technical Field

[0001] This invention relates to an organosilicon coating adhesive, and more particularly to a UV / moisture dual-curing composition, its preparation method, and its application. Background Technology

[0002] Organosilicon materials possess excellent properties such as resistance to high and low temperatures, weather resistance, corrosion resistance, and physiological inertness, and are widely used in the bonding and sealing protection of structural components, optical components, and electrical and electronic components.

[0003] UV / moisture dual-curing technology combines the rapid prototyping advantages of UV curing with the dark-area curing capabilities of moisture curing. It improves upon the problems of long curing time, low efficiency, and high cost associated with pure moisture curing technology, while also solving the issue of UV curing's inability to cure in dark areas of complex structures, thus broadening its application scenarios. Therefore, the development and application of UV / moisture dual-curing materials, especially silicone-based UV / moisture dual-curing materials, have high application and market value. However, common UV / moisture dual-curing compositions generally suffer from poor storage stability due to incompatibility between moisture curing catalysts and acrylate diluents with the main component, siloxane. During storage, problems such as gelation, delamination, and photoinitiator precipitation easily occur, leading to significant performance degradation during use and limiting the lifespan and applications of UV / moisture dual-curing compositions.

[0004] Patent CN112062964A discloses a UV / moisture dual-curing composition and a preparation process for an acrylate-polysiloxane material. The main structure contains both isocyanate and alkoxysilane groups, achieving UV / moisture dual curing. The resulting polysiloxane material has a regular and simple structure, good transparency, and excellent room temperature storage stability, reducing the gelation problem that easily occurs during the production and storage of UV / moisture dual-curing compositions. However, the production process of this acrylate-polysiloxane material uses solution polymerization and ethanol washing, making large-scale production difficult and thus limiting its application.

[0005] Patent CN111471425B describes the addition of polyether-type polyurethane oligomers with (meth)acryloyloxy and alkoxysilane functional groups to a UV / moisture dual-curing composition. This improves the system's compatibility and storage performance, resulting in a composition with high adhesive strength, good storage stability, safety, and environmental friendliness. However, while this method improves storage performance, the reduced siloxane content inevitably leads to a decrease in the coating's weather resistance, affecting its protective performance for structural, optical, and electronic components.

[0006] Therefore, there is a need to provide a UV / moisture dual-curing composition that can effectively solve the problem of storage stability, maintain the product's adhesion, protection, and weather resistance, extend the service life of the UV / moisture dual-curing composition, and broaden the applications of the UV / moisture dual-curing composition. Summary of the Invention

[0007] To address the above technical problems, this invention proposes a UV / moisture dual-curing silicone resin composition, its preparation method, and its applications. The composition exhibits excellent storage stability, deep curing depth, low light curing energy, high curing efficiency, and excellent protective properties. The composition retains effective performance even after prolonged storage.

[0008] On one hand, the present invention provides a UV / moisture dual-curing silicone resin composition, the composition comprising the following components:

[0009] (A) Acrylic-modified silicone resin, content 85-96wt%;

[0010] (B) Photoinitiator, content 0.5-2wt%;

[0011] (C) Acrylic ester diluent, content 1-5wt%;

[0012] (D) Organometallic catalyst 0.5-2wt%;

[0013] (E) Polyether-modified silicone oil 1-5 wt%;

[0014] (F) Auxiliary agents 0.02-1wt%.

[0015] As a preferred embodiment of the present invention, the structure of component A is as shown in Formula I and / or Formula II:

[0016]

[0017]

[0018] Wherein, R1, R2, R3, R4, R5, and R6 independently represent hydrogen atoms, C1-C10 alkyl groups, aromatic hydrocarbon groups, and alkenyl groups, preferably methyl groups; where a and b refer to the degree of polymerization, with values ​​ranging from a to 100 to 450, respectively, preferably a to 200 to 300, and b to 200 to 300.

[0019] As a preferred embodiment of the present invention, the preparation method of component A is as follows:

[0020] (1) Hydroxy silicone oil and methacryloxypropyltrimethoxysilane (or methacryloyloxypropyltrimethoxysilane) are added to a reactor under a nitrogen atmosphere, mixed, and heated to 55-60°C; wherein the viscosity range of the hydroxy silicone oil is 500-1500 cp, preferably 750-1000 cp, and the molar ratio of the feed is n. 硅烷 :n Si-OH =2~5, the preferred molar ratio of feed is n 硅烷 :n Si-OH =3~4;

[0021] (2) Add 1% to 10 wt% lithium methyl ethanol solution to the reactor and maintain the reaction at 55 to 60°C for 2 to 3 hours; wherein, the amount of lithium methyl ethanol solution added is based on maintaining the Li content of the system at 1 to 5 ppm, preferably the Li content at 2 to 4 ppm;

[0022] (3) After cooling to room temperature, remove the generated methanol under a negative pressure of 30-70 mbar for 1-2 hours;

[0023] (4) Continuously introduce CO2 into the reactor to inactivate lithium methoxide for 1-2 hours;

[0024] (5) Component A is obtained. The product is poured into a container under nitrogen atmosphere and sealed for storage.

[0025] As a preferred embodiment of the present invention, component B is selected from one or more of 2-methyl-1-[4-(methylthio)phenyl]-2-(4-morpholinyl)-1-propanone (also known as 907), 2-phenylbenzyl-2-dimethylamine-1-(4-morpholinylbenzylphenyl)butanone (also known as 369), diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide (also known as TPO), ethyl 2,4,6-trimethylbenzoylphenylphosphonate (also known as TPO-L), phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide (also known as 819), 2-isopropylthioxanthanone (also known as ITX), 2,4-diethylthioxanthanone (also known as DETX), 2-chlorothioxanthanone (also known as CTX), and 1-chloro-4-propoxythioxanthanone (also known as CPTX), and can be selected according to the wavelength of the UV light source.

[0026] As a preferred embodiment of the present invention, component C is selected from one or more of 1,6-hexanediol diacrylate (also known as HDDA), tripropylene glycol diacrylate (also known as TPGDA), trimethylolpropane triacrylate (also known as TMPTA), and 2-phenylethyl acrylate (also known as PEA).

[0027] As a preferred embodiment of the present invention, component D is selected from one or more of dibutyltin dilaurate, stannous octoate, diisopropyl bis(acetoacetic acid) titanate, tetra-tert-butyl titanate, bismuth isooctanoate, and bismuth laurate.

[0028] As a preferred embodiment of the present invention, the structure of component E is shown in Formula III:

[0029]

[0030] R7 and R8 each independently represent alkyl, alkoxy, aromatic hydrocarbon, or alkenyl groups with 1-20 hydrogen or carbon atoms; R9 represents alkyl, alkyl ester, or epoxy groups with 1-5 hydrogen or carbon atoms; m, n, o, p, x, y, and z all refer to the degree of polymerization, with values ​​ranging from m=0-10, n=1-40, o=40-400, p=1-10, x=1-20, y=0-20, z=1-10, preferably m=0-4, n=1-10, o=50-100, p=1-3, x=5-10, y=0-5, z=1-5.

[0031] As a preferred embodiment of the present invention, the preparation method of component E is as follows:

[0032] (1) Hydrogen-containing silicone oil and hydroxyl vinyl silicone oil are added to a reactor under a nitrogen atmosphere, mixed, and heated to 60-80°C; wherein the molar ratio of hydrogen-containing silicone oil to hydroxyl vinyl silicone oil is n Si-H :n Vi =41~440, preferably n Si-H :n Vi =2~13;

[0033] (2) Add a cassiterite catalyst to the reactor and maintain the temperature at 60-80°C for 0.5-1 h for the addition reaction; wherein the amount of cassiterite catalyst added is 1-5 ppm of the Pt content in the system;

[0034] (3) Add allyl polyether to the reactor, mix and heat to 80-110℃; wherein, the amount of allyl polyether added is n molar ratio. 烯丙基 :n Si-H =1.3~1.6;

[0035] (4) Add the cassiterite catalyst to the reactor and maintain the addition reaction at 80-110°C for 0.5-1 h;

[0036] (5) Component E is obtained. After the product cools to room temperature, it is poured into a container under nitrogen atmosphere and sealed for storage.

[0037] In a preferred embodiment of the present invention, component F comprises one or more of a stabilizer, a dehydrating agent, a thixotropic agent, and a fluorescent whitening agent. The stabilizer is selected from one or more of hydroquinone, p-hydroxyanisole, 2,6-di-tert-butyl-p-cresol, 2,6-di-tert-butylhydroquinone, and 2-tert-butylhydroquinone; the dehydrating agent is selected from one or more of methyltrimethoxysilane and vinyltrimethoxysilane; the thixotropic agent is selected from hydrophobic fumed silica; and the fluorescent whitening agent is fluorescent whitening agent OB.

[0038] On the other hand, the present invention also provides a method for preparing the UV / moisture dual-curing silicone resin composition as described above, the method comprising the following steps:

[0039] (1) Mix component A and component E and dehydrate under reduced pressure, then seal and set aside for later use;

[0040] (2) Mix component B with component C so that component B is completely dissolved in component C;

[0041] (3) The mixture of dehydrated component A and component E, the mixture of component B and component C, component D and component F are sequentially added to a reactor under a nitrogen atmosphere and mixed to obtain a UV / moisture dual-curing silicone resin composition.

[0042] Preferably, in step (1), the temperature for dehydration of component A and component E under reduced pressure is 50-100℃, preferably 60-80℃; the pressure is 10-100mbar, preferably 40-60mbar; and the time is 0.5-3h, preferably 1-2h.

[0043] Preferably, in step (2), the mixing temperature of component B and component C is 20-50℃, preferably 30-40℃; the mixing speed is 100-400rpm, preferably 200-300rpm; and the mixing time is 10-50min, preferably 30-40min.

[0044] Preferably, in step (3), the mixing temperature of each component in the reactor under nitrogen atmosphere is 10-40℃, preferably 20-35℃; the mixing speed is 100-400rpm, preferably 200-300rpm; and the mixing time is 0.5-3h, preferably 1-2h.

[0045] An application of the UV / moisture dual-curing silicone resin composition as described above, the application including protection of electronic product encapsulation or circuit solder joints; and bonding of materials such as metals, glass, and plastics.

[0046] The beneficial effects of this invention are as follows:

[0047] 1. The UV / moisture dual-curing silicone resin composition obtained by the present invention contains polyether-modified silicone oil, which can efficiently emulsify siloxane resin and acrylate diluent, improve their compatibility, and significantly improve the storage stability of the composition; it can achieve a curing depth of more than 10 cm, thus broadening its application in solder joint protection.

[0048] 2. The polyether-modified silicone oil used in this invention has Si-OH in its structure that can participate in the moisture curing reaction, which improves the compatibility of the composition without causing a decrease in the adhesive performance and protective performance of the coated adhesive product.

[0049] 3. The UV / moisture dual-curing silicone resin composition obtained by the present invention can be used with light sources of different UV wavelengths by combining photoinitiators. Short-wavelength UV curing can be achieved at wavelengths up to 200nm, while long-wavelength UV curing can be achieved at wavelengths of 385nm, 395nm, and even 405nm. Detailed Implementation

[0050] The present invention will be further illustrated below with specific embodiments. These embodiments are merely illustrative and do not limit the scope of the invention.

[0051] Unless otherwise specified, all raw materials and reagents used in this invention can be purchased commercially.

[0052] The main testing methods used in the following embodiments of the present invention are as follows:

[0053] Viscosity testing method: Measured using a rotational viscometer;

[0054] UV curing test method: UV curing was performed using an LED + UV mercury lamp curing chamber (model GQ6K-2leda-2), and UV energy was recorded using a UV energy meter;

[0055] Moisture curing test method: Place in an environment of 25℃ / 50%RH, perform finger pressure test every 5 minutes, and record the surface drying time;

[0056] Test method for volatile matter: After UV curing, place in an environment of 25℃ / 50%RH for 7 days respectively.

[0057] The mass change was measured using a forced-air drying oven at 70℃ for 2 hours;

[0058] Hardness testing method: Measured using a Shore hardness tester;

[0059] Method for testing curing depth: Measured using a ruler;

[0060] Storage stability test: The viscosity of the adhesive composition was tested after being placed in a 70°C constant temperature chamber for 7, 14, and 30 days under sealed conditions. According to the accelerated aging formula, the storage time at room temperature (23°C) for 7 days and 14 days at 70°C is 6 months and 1 year, respectively.

[0061] Example A-1

[0062] 300g of hydroxyl silicone oil (107v1000, Jiangsu Kexing) and 30g of acryloyloxypropyltrimethoxysilane (Jingzhou Jianghan) were mixed in a reactor under a nitrogen atmosphere. The mixture was heated to 60℃, and 64μL of 2.2M lithium methoxide methanol solution (Shaoxing Shangyu Hualun) was added. The reaction was carried out for 2 hours. After cooling to room temperature, the pressure was gradually reduced to 50mbar to remove methanol for 1 hour. CO2 was continuously introduced into the reactor to inactivate lithium methoxide for 1 hour. The product was poured into a nitrogen atmosphere container and sealed for storage to obtain component A-1.

[0063] Example A-2

[0064] 300g of hydroxyl silicone oil (107v1000, Jiangsu Kexing) and 32g of methacryloxypropyltrimethoxysilane (Jingzhou Jianghan) were mixed in a reactor under a nitrogen atmosphere. The mixture was heated to 60℃, and 64μL of 2.2M lithium methoxide methanol solution (Shaoxing Shangyu Hualun) was added. The reaction was carried out for 2 hours. After cooling to room temperature, the pressure was gradually reduced to 50mbar to remove methanol for 1 hour. CO2 was continuously introduced into the reactor to inactivate lithium methoxide for 1 hour. The product was poured into a nitrogen atmosphere container and sealed for storage to obtain component A-2.

[0065] Example E-1

[0066] 638g of methyl hydrogen silicone oil (self-made) and 104g of hydroxyvinyl silicone oil (self-made) were added to a reactor under a nitrogen atmosphere, mixed and heated to 70°C. 61μL of caster catalyst (Pt20000, Shanghai Silicon Power) was added to the reactor and the reaction was carried out for 0.5h. 156g of allyl polyether (B400, Zhongshan Chemical) was added to the reactor and the temperature was raised to 90°C. 61μL of caster catalyst (Pt20000, Shanghai Silicon Power) was added to the reactor and the reaction was carried out for 0.5h. The product was poured into a nitrogen atmosphere container and sealed for storage to obtain component E-1.

[0067] Comparative Example E-2

[0068] 638g of methyl hydrogen silicone oil (self-made) and 156g of allyl polyether (B400, Zhongshan Chemical) were heated to 90℃, and 61μL of caster catalyst (Pt20000, Shanghai Silicon Power) was added to the reactor. The reaction was carried out for 0.5h, and the product was poured into a nitrogen atmosphere container and sealed for storage to obtain component E-2.

[0069] Example

[0070] Different UV / moisture dual-curing silicone resin compositions in Examples 1-4 were prepared using the formulations in Table 1. The preparation methods are as follows:

[0071] (1) Acrylic modified silicone resin and polyether modified silicone oil were pretreated, mixed, and then dehydrated under reduced pressure at 60℃ / 50mbar for 1 hour, and then sealed for later use.

[0072] (2) Pretreatment of component B and component C: mix at 40℃ / 200rpm for 30min to completely dissolve component B in component C;

[0073] (3) The dehydrated mixture of component A and component E, the mixture of component B and component C, component D and component F are added sequentially to a reactor under nitrogen atmosphere and mixed at 25℃ / 250rpm for 1h.

[0074] (4) Pour the product into a light-proof container under a nitrogen atmosphere and seal it for storage.

[0075] Table 1. UV / Moisture Dual-Cure Silicone Resin Compositions

[0076]

[0077] The compositions provided in Examples 1-4 and Comparative Application Examples 1-3 were subjected to the performance tests shown in Table 2, and the results are as follows:

[0078] Table 2. Performance Test Results

[0079]

[0080] As can be seen from the performance data in Table 2, Examples 1-4 showed superior performance in the heat storage test compared to Comparative Example 1, and the UV curing depth was deeper, indicating that the composition of the present invention has the advantages of good storage stability and deep curing depth. On the other hand, the hardness and volatile matter of the products in Examples 1-4 did not change significantly, while the hardness of the product in Comparative Example 2 decreased significantly, and the volatile matter increased significantly.

[0081] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several improvements and additions without departing from the method of the present invention, and these improvements and additions should also be considered within the scope of protection of the present invention.

Claims

1. A UV / moisture dual-curing silicone resin composition, said composition comprising the following components: (A) Acrylic-modified silicone resin, content 85-96wt%; (B) Photoinitiator, content 0.5-2wt%; (C) Acrylic ester diluent, content 1-5wt%; (D) Organometallic catalyst 0.5-2wt%; (E) Polyether-modified silicone oil 1-5 wt%; (F) Auxiliary agents 0.02-1wt%.

2. The UV / moisture dual-curing silicone resin composition as described in claim 1, characterized in that, The structure of component A is shown in Formula I and / or Formula II: Wherein, R1, R2, R3, R4, R5, and R6 independently represent hydrogen atoms, C1-C10 alkyl groups, aromatic hydrocarbon groups, and alkenyl groups, preferably methyl groups; where a and b refer to the degree of polymerization, with values ​​ranging from a to 100 to 450, respectively, preferably a to 200 to 300, and b to 200 to 300.

3. The UV / moisture dual-curing silicone resin composition as described in claim 1 or 2, characterized in that, Component B is selected from one or more of the following: 2-methyl-1-[4-(methylthio)phenyl]-2-(4-morpholinyl)-1-propanone (also known as 907), 2-phenylbenzyl-2-dimethylamine-1-(4-morpholinylbenzylphenyl)butanone (also known as 369), diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide (also known as TPO), ethyl 2,4,6-trimethylbenzoylphenylphosphonate (also known as TPO-L), phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide (also known as 819), 2-isopropylthioxanthanone (also known as ITX), 2,4-diethylthioxanthanone (also known as DETX), 2-chlorothioxanthanone (also known as CTX), and 1-chloro-4-propoxythioxanthanone (also known as CPTX).

4. The UV / moisture dual-curing silicone resin composition according to any one of claims 1-3, characterized in that, Component C is selected from one or more of 1,6-hexanediol diacrylate (also known as HDDA), tripropylene glycol diacrylate (also known as TPGDA), trimethylolpropane triacrylate (also known as TMPTA), and 2-phenylethyl acrylate (also known as PEA).

5. The UV / moisture dual-curing silicone resin composition according to any one of claims 1-4, characterized in that, Component D is selected from one or more of dibutyltin dilaurate, stannous octanoate, diisopropyl bis(acetoacetic acid) titanate, tetra-tert-butyl titanate, bismuth isooctanoate, and bismuth laurate.

6. The UV / moisture dual-curing silicone resin composition according to any one of claims 1-5, characterized in that, The structure of component E is shown in Formula III: R7 and R8 each independently represent alkyl, alkoxy, aromatic hydrocarbon, or alkenyl groups with 1-20 hydrogen or carbon atoms; R9 represents alkyl, alkyl ester, or epoxy groups with 1-5 hydrogen or carbon atoms; m, n, o, p, x, y, and z all refer to the degree of polymerization, with values ​​ranging from m=0-10, n=1-40, o=40-400, p=1-10, x=1-20, y=0-20, z=1-10, preferably m=0-4, n=1-10, o=50-100, p=1-3, x=5-10, y=0-5, z=1-5.

7. The UV / moisture dual-curing silicone resin composition according to any one of claims 1-6, characterized in that, Component F includes one or more of a stabilizer, a dehydrating agent, a thixotropic agent, and a fluorescent whitening agent. The stabilizer is selected from one or more of hydroquinone, p-hydroxyanisole, 2,6-di-tert-butyl-p-cresol, 2,6-di-tert-butylhydroquinone, and 2-tert-butylhydroquinone; the dehydrating agent is selected from one or more of methyltrimethoxysilane and vinyltrimethoxysilane; the thixotropic agent is selected from hydrophobic fumed silica; and the fluorescent whitening agent is fluorescent whitening agent OB.

8. A method for preparing the UV / moisture dual-curing silicone resin composition according to any one of claims 1-7, the method comprising the following steps: (1) Mix component A and component E and dehydrate under reduced pressure, then seal and set aside for later use; (2) Mix component B with component C so that component B is completely dissolved in component C; (3) The mixture of dehydrated component A and component E, the mixture of component B and component C, component D and component F are sequentially added to a reactor under a nitrogen atmosphere and mixed to obtain a UV / moisture dual-curing silicone resin composition.

9. The preparation method according to claim 8, characterized in that, In step (1), the dehydration temperature of component A and component E during vacuum dehydration is 50-100℃, preferably 60-80℃; the pressure is 10-100mbar, preferably 40-60mbar; and the time is 0.5-3h, preferably 1-2h. In step (2), the mixing temperature of component B and component C is 20-50℃, preferably 30-40℃; the mixing speed is 100-400rpm, preferably 200-300rpm; and the mixing time is 10-50min, preferably 30-40min. In step (3), the mixing temperature of each component in a reactor under nitrogen atmosphere is 10-40℃, preferably 20-35℃; the mixing speed is 100-400rpm, preferably 200-300rpm; and the mixing time is 0.5-3h, preferably 1-2h.

10. The UV / moisture dual-curing silicone resin composition according to any one of claims 1-7 or the UV / moisture dual-curing silicone resin composition prepared by the preparation method according to any one of claims 8 or 9, in the encapsulation of electronic products or the protection of circuit solder joints or in the bonding of materials such as metals, glass, and plastics.

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