Organosilicone modified acrylic resin and preparation method and application thereof

Abstract

The invention provides organic silicon modified acrylic resin as well as a preparation method and application thereof. The organic silicon modified acrylic resin is prepared from 40 to 60 parts of methyl methacrylate, 30 to 40 parts of butyl acrylate, 3 to 8 parts of acrylic acid, 10 to 20 parts of a bifunctional organic silicon monomer, 58 to 63 parts of a solvent, 0.3 to 0.8 part of an initiator component A, 0.2 to 0.5 part of an initiator component B, 5 to 15 parts of a fluorine-containing acrylic monomer and 0.1 to 0.5 part of an epoxy ring-opening catalyst. The bifunctional organic silicon monomer simultaneously contains an acryloyloxy group and an epoxy group, and the olefine acid monomer and the bifunctional organic silicon monomer can form a Si-O-C cross-linked network, so that synchronous construction of chemical bonds and the cross-linked network is realized. When the resin is prepared, controllable construction of a molecular structure is realized through accurate temperature regulation and control in different stages. The organosilicon modified acrylic resin overcomes the problem of phase separation, has excellent heat resistance, hydrophobicity, adhesive force and mechanical properties, has dimensional stability in a wide temperature range of-40 DEG C to 150 DEG C, still keeps an extremely low level of dielectric constant and dielectric loss after 85 DEG C / 85% RH aging, and has excellent comprehensive properties.

Description

Technical Field

[0001] The present invention relates to the field of acrylic resins, and in particular to an organosilicon-modified acrylic resin and a preparation method and application thereof. Background Art

[0002] With the rapid development of 5G communications, the Internet of Things, and flexible electronics, electronic packaging materials face unprecedented performance challenges. While traditional acrylic resins offer excellent processing properties and bonding strength, their heat resistance, dielectric properties, and wet-heat stability make them difficult to meet the packaging requirements of high-frequency, high-speed electronic devices. Silicone materials, while offering excellent heat resistance and dielectric properties, have poor compatibility with acrylic resins, easily leading to phase separation and severely impacting the material's mechanical properties and long-term reliability.

[0003] At present, the preparation methods of silicone-modified acrylic resins mainly include conventional polymerization methods such as solution polymerization and emulsion polymerization. Existing silicone-modified acrylic resins mostly use monofunctional silicon and acrylic monomer copolymerization, but due to the poor compatibility between the siloxane segment and the acrylic segment, phase separation is prone to occur, resulting in low coating adhesion. In addition, the traditional one-step polymerization process is difficult to simultaneously optimize heat resistance and hydrophobicity. In the traditional preparation process, the mixing uniformity of silicone monomers and acrylate monomers is difficult to accurately control, resulting in less than ideal distribution of silicone in the resin, affecting the material properties. At the same time, commonly used cross-linking methods, such as chemical initiator-induced cross-linking, have problems such as initiator residue and difficult to control cross-linking reactions, which limit the further improvement of the performance of silicone-modified acrylic resins. Although there are some improved polymerization and cross-linking methods in the existing technology, there is still a lack of a preparation technology that can achieve precise gradient mixing of monomers and efficient in-situ cross-linking to prepare silicone-modified acrylic resins with better overall performance, unique structure and properties.

[0004] CN115594797A discloses an acrylic modified silicone resin, a coating, and a preparation method thereof, comprising the following raw materials: 10-20 parts by weight of a monofunctional acrylate compound, 8-15 parts of a difunctional acrylate compound, 25-45 parts of an organosilicon monomer, and 50-60 parts of a first auxiliary agent. The coating, prepared by the interaction of the various components in this patent application, exhibits high water resistance, corrosion resistance, antifouling properties, and impact resistance, fully meeting customer needs. However, the resin cannot withstand high temperatures and has limited water resistance, which limits its application scenarios. Summary of the Invention

[0005] In view of this, the present invention aims to provide a silicone-modified acrylic resin and its preparation method and application, so as to solve the problems of poor heat resistance and hydrophobicity of the resin and limited use.

[0006] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0007] The present invention provides an organosilicon-modified acrylic resin, which comprises the following components in parts by weight: 40-60 parts of methyl methacrylate, 30-40 parts of butyl acrylate, 3-8 parts of acrylic acid, 10-20 parts of a bifunctional organosilicon monomer, 58-63 parts of a solvent, 0.3-0.8 parts of an initiator component A, 0.2-0.5 parts of an initiator component B, 5-15 parts of a fluorine-containing acrylic monomer, and 0.1-0.5 parts of an epoxy ring-opening catalyst.

[0008] Furthermore, the structural formula of the bifunctional silicone monomer is CH2=CHCOO-(Si-O)n-CH2CH(O)CH2, wherein n=3~5.

[0009] Furthermore, the fluorine-containing acrylic monomer is selected from any one of hexafluorobutyl methacrylate and perfluorohexylethyl methacrylate.

[0010] Furthermore, the epoxy ring-opening catalyst is tetraisopropyl titanate.

[0011] Furthermore, the initiator component A is ammonium persulfate, and the initiator component B is ascorbic acid.

[0012] Furthermore, the solvent is propylene glycol methyl ether acetate.

[0013] The present invention also provides a method for preparing the above-mentioned organosilicon-modified acrylic resin, comprising the following steps:

[0014] Prepolymerization stage: methyl methacrylate, butyl acrylate, acrylic acid, bifunctional silicone monomer and solvent are mixed, heated to a first temperature condition, and aqueous solutions of initiator component A and initiator component B are added dropwise to initiate a free radical polymerization reaction to form a core-shell prepolymer;

[0015] Chain extension stage: heating to the second temperature condition, adding fluorinated acrylate monomer, and continuing the reaction;

[0016] Cross-linking stage: heating to the third temperature condition and adding epoxy ring-opening catalyst;

[0017] Post-processing stage: cooling to the fourth temperature condition, adjusting the pH to 6-7, and filtering to obtain the silicone-modified acrylic resin.

[0018] Furthermore, in the prepolymerization stage, the first temperature condition is 60~70°C, initiating a free radical polymerization reaction for 1~2 hours to form a core-shell prepolymer; in the chain extension stage, the second temperature condition is 80~90°C, adding a fluorinated acrylate monomer, and continuing the reaction for 2~3 hours; in the cross-linking stage, the third temperature condition is 110~120°C, adding an epoxy ring-opening catalyst, and keeping warm for 2~4 hours; in the post-processing stage, the fourth temperature condition is 40~50°C.

[0019] The present invention also proposes the use of the above-mentioned organosilicon-modified acrylic resin as a packaging adhesive in electronic packaging materials.

[0020] The present invention also proposes the use of the above-mentioned organosilicon-modified acrylic resin in film-forming materials.

[0021] Compared with the prior art, the organosilicon-modified acrylic resin and its preparation method and application described in the present invention have the following advantages:

[0022] (1) The bifunctional silicone monomer contains both acryloxy and epoxy groups. The acrylate monomer and the bifunctional silicone monomer can form a Si-OC cross-linking network, realizing the simultaneous construction of chemical bonds and cross-linking networks, and significantly improving the comprehensive performance of silicone-modified acrylic resins.

[0023] (2) A gradient temperature control process was used during the resin preparation process. By precisely controlling the different temperatures at different stages, the molecular structure can be controlled, which helps to improve the overall performance of the resin. By precisely controlling the gradient distribution of the cross-linking density, the material exhibits unprecedented dimensional stability (thermal expansion coefficient ≤ 30ppm / ℃) over a wide temperature range of -40℃ to 150℃, solving the long-standing thermal mismatch problem in the electronic packaging field.

[0024] (3) The silicone-modified acrylic resin of the present invention overcomes the phase separation problem and has excellent heat resistance, hydrophobicity, adhesion, and mechanical properties. After aging for 1000 hours at 85°C / 85%RH, the dielectric constant (≤2.8) and dielectric loss (≤0.005) remain at extremely low levels, and the overall performance is excellent. DETAILED DESCRIPTION

[0025] The present invention will be further described below in conjunction with specific embodiments. It should be noted that the data in the following experimental examples are obtained by the inventor through a large number of experiments. Due to space limitations, only a portion thereof is shown in the specification, and those skilled in the art can understand and implement the present invention under these data. These embodiments are merely intended to illustrate the present invention and are not intended to limit the scope of the present invention. It should also be understood that, after having read the contents of the present invention, those skilled in the art may make various changes or modifications to the present invention, and these changes or modifications also fall within the scope protected by this application.

[0026] In order to solve the phase separation problem of traditional silicone-modified acrylic resins while making them have excellent heat resistance, hydrophobicity and adhesion, the present invention provides a silicone-modified acrylic resin, comprising the following components in parts by weight: 40-60 parts of methyl methacrylate, 30-40 parts of butyl acrylate, 3-8 parts of acrylic acid, 10-20 parts of a bifunctional silicone monomer, 58-63 parts of a solvent, 0.3-0.8 parts of an initiator component A, 0.2-0.5 parts of an initiator component B, 5-15 parts of a fluorine-containing acrylic monomer, and 0.1-0.5 parts of an epoxy ring-opening catalyst.

[0027] The structural formula of the bifunctional silicone monomer is CH2=CHCOO-(Si-O)n-CH2CH(O)CH2, wherein n=3~5.

[0028] The fluorine-containing acrylic monomer is selected from any one of hexafluorobutyl methacrylate and perfluorohexylethyl methacrylate.

[0029] The epoxy ring-opening catalyst is tetraisopropyl titanate.

[0030] The initiator A component is ammonium persulfate, and the initiator B component is ascorbic acid.

[0031] The solvent is propylene glycol methyl ether acetate.

[0032] Based on the above-mentioned organosilicon-modified acrylic resin, the present invention further provides a method for preparing the organosilicon-modified acrylic resin, comprising the following steps:

[0033] Prepolymerization stage: methyl methacrylate, butyl acrylate, acrylic acid, bifunctional silicone monomer and solvent are mixed, heated to a first temperature condition, and aqueous solutions of initiator component A and initiator component B are added dropwise to initiate a free radical polymerization reaction to form a core-shell prepolymer;

[0034] Chain extension stage: heating to the second temperature condition, adding fluorinated acrylate monomer, and continuing the reaction;

[0035] Cross-linking stage: heating to the third temperature condition, adding epoxy ring-opening catalyst to open the epoxy group to form a Si-OC cross-linking network;

[0036] Post-processing stage: cooling to the fourth temperature condition, adjusting the pH to 6-7, and filtering to obtain the silicone-modified acrylic resin.

[0037] Specifically, in the prepolymerization stage, the first temperature condition is 60~70°C, initiating a free radical polymerization reaction for 1~2 hours to form a core-shell prepolymer; in the chain extension stage, the second temperature condition is 80~90°C, adding a fluorinated acrylate monomer, and continuing the reaction for 2~3 hours; in the cross-linking stage, the third temperature condition is 110~120°C, adding an epoxy ring-opening catalyst, and keeping warm for 2~4 hours; in the post-processing stage, the fourth temperature condition is 40~50°C.

[0038] The acrylic monomer combination utilizes methyl methacrylate, butyl acrylate, and acrylic acid, along with a bifunctional silicone monomer containing both acryloxy and epoxy groups. The acryloxy groups are capable of participating in free radical polymerization, while the epoxy groups serve as high-temperature crosslinking sites, enabling the simultaneous construction of chemical bonds and a crosslinked network. The acrylic monomers and bifunctional silicone monomers form a Si-OC crosslinked network, achieving the simultaneous construction of chemical bonds and a crosslinked network, significantly improving the overall performance of the silicone-modified acrylic resin. This unique in-situ crosslinking mechanism ensures that the resin maintains extremely low dielectric constant (≤2.8) and dielectric loss (≤0.005) even after aging for 1000 hours at 85°C / 85% RH, fully meeting the requirements for 5G high-frequency signal transmission. Furthermore, a chemically bonded network of silicone and acrylic segments is constructed at the molecular level, ensuring the resin maintains excellent mechanical properties.

[0039] Furthermore, the addition of a fluorinated acrylate monomer enhances hydrophobicity. A composite initiator system of ammonium persulfate and ascorbic acid, with redox initiators enabling efficient low-temperature initiation, and the use of tetraisopropyl titanate, a Lewis acid catalyst, enables precise high-temperature crosslinking. These components synergize to form a core-shell prepolymer during the prepolymerization stage, introduce fluorinated segments during the chain extension stage, and catalyze the ring-opening of epoxy groups during the crosslinking stage to form a Si-OC crosslinked network. The resulting silicone-modified acrylic overcomes phase separation and exhibits excellent heat resistance (Tg ≥ 120°C), hydrophobicity (water contact angle ≥ 110°), and adhesion (cross-hatch grade 0).

[0040] In addition to the selection of components, a gradient temperature control process is employed during preparation. By precisely regulating temperatures at different stages, the molecular structure is controlled, contributing to improved resin performance. By precisely controlling the gradient distribution of crosslink density, the material exhibits unprecedented dimensional stability (thermal expansion coefficient ≤ 30ppm / °C) across a wide temperature range of -40°C to 150°C, resolving the long-standing thermal mismatch problem in the electronic packaging field.

[0041] The organosilicon-modified acrylic resin of the present invention is particularly suitable for use as packaging adhesive or as film-forming material in electronic packaging materials with higher requirements.

[0042] The present invention is described below with reference to specific embodiments.

[0043] Example 1

[0044] Raw materials preparation:

[0045] Methyl methacrylate (MMA) 50g, butyl acrylate (BA) 30g, acrylic acid (AA) 5g, difunctional silicone monomer 15g (structural formula: CH2=CHCOO(Si-O)3CH2CH(O)CH2), hexafluorobutyl methacrylate (HFMA) 10g, ammonium persulfate (APS) 0.5g, ascorbic acid (Vc) 0.3g, tetraisopropyl titanate 0.2g, propylene glycol methyl ether acetate (PMA) 60g.

[0046] Under nitrogen protection, MMA, BA, AA, and bifunctional silicone monomers were dissolved in PMA and heated to 65°C. APS and Vc were prepared into a 5wt% aqueous solution, and the aqueous solution of APS and Vc was slowly added dropwise, maintaining the reaction at 65°C for 1.5 hours.

[0047] The temperature was raised to 85°C, HFMA was added, and the reaction was continued for 2 h.

[0048] The temperature was raised to 115°C, tetraisopropyl titanate was added, and the temperature was kept for 3 h.

[0049] The temperature was lowered to 50° C., triethylamine was added to adjust the pH to 6.5, and the mixture was filtered to obtain a transparent silicone-modified acrylic resin.

[0050] Example 2

[0051] Methyl methacrylate (MMA) 40g, butyl acrylate (BA) 40g, acrylic acid (AA) 3g, difunctional silicone monomer 10g (structural formula: CH2=CHCOO(Si-O)3CH2CH(O)CH2), hexafluorobutyl methacrylate (HFMA) 5g, ammonium persulfate (APS) 0.3g, ascorbic acid (Vc) 0.2g, tetraisopropyl titanate 0.1g, propylene glycol methyl ether acetate (PMA) 58g.

[0052] Under nitrogen protection, MMA, BA, AA, and bifunctional silicone monomers were dissolved in PMA and heated to 70°C. APS and Vc were prepared into a 6 wt% aqueous solution, and the aqueous solution of APS and Vc was slowly added dropwise, maintaining the reaction at 70°C for 2 hours.

[0053] The temperature was raised to 90°C, HFMA was added, and the reaction was continued for 3 h.

[0054] Raise the temperature to 110°C, add tetraisopropyl titanate, and keep warm for 2 hours.

[0055] The temperature was lowered to 40° C., triethylamine was added to adjust the pH to 6.0, and the mixture was filtered to obtain a transparent silicone-modified acrylic resin.

[0056] Example 3

[0057] Methyl methacrylate (MMA) 60g, butyl acrylate (BA) 35g, acrylic acid (AA) 8g, difunctional silicone monomer 20g (structural formula: CH2=CHCOO(Si-O)5CH2CH(O)CH2), perfluorohexylethyl methacrylate 15g, ammonium persulfate (APS) 0.8g, ascorbic acid (Vc) 0.5g, tetraisopropyl titanate 0.5g, propylene glycol methyl ether acetate (PMA) 63g.

[0058] Under nitrogen protection, MMA, BA, AA, and bifunctional silicone monomers were dissolved in PMA and heated to 60°C. APS and Vc were prepared into a 6 wt% aqueous solution, and the aqueous solution of APS and Vc was slowly added dropwise, and the reaction was maintained at 60°C for 1 hour.

[0059] The temperature was raised to 80°C, perfluorohexylethyl methacrylate was added, and the reaction was continued for 2.5 hours.

[0060] The temperature was raised to 120°C, tetraisopropyl titanate was added, and the temperature was kept for 4 h.

[0061] The temperature was lowered to 45° C., triethylamine was added to adjust the pH to 7.0, and the mixture was filtered to obtain a transparent silicone-modified acrylic resin.

[0062] Comparative Example 1

[0063] The component selection and dosage of Comparative Example 1 are the same as those of Example 1, except that KH750 is used instead of the difunctional monomer.

[0064] Under nitrogen protection, MMA, BA, AA and KH750 monomers were dissolved in PMA and heated to 80°C. APS and Vc were prepared into a 5 wt% aqueous solution, and the aqueous solution of APS and Vc was slowly added dropwise and reacted at 80°C for 4 h.

[0065] Comparative Example 2

[0066] The components and preparation method of Comparative Example 2 are the same as those of Example 1, except that the temperature in the prepolymerization stage, chain extension stage and crosslinking stage is 80°C.

[0067] The organosilicon-modified acrylic resins prepared in Examples 1-3 and Comparative Examples 1-2 were tested, and the specific results are shown in Table 1.

[0068] Table 1

[0069]

[0070]

[0071] The resins of Examples 1 to 3 and Comparative Example 2 showed no phase separation after storage for 30 days, while the resin of Comparative Example 1 showed phase separation after storage for 30 days.

[0072] As can be seen from Table 1, the organosilicon-modified acrylic resins of Examples 1 to 3 construct a chemical bonding network of organosilicon and acrylic segments at the molecular level, which gives the resin excellent mechanical properties and good bending resistance, and can be used for film-forming materials. However, the elongation at break of Comparative Examples 1 and 2 is low, cracks easily appear after bending, and the tensile strength is also low. The use of Examples 1 to 3 of the present invention achieves a perfect combination of good heat resistance above 120°C and super-hydrophobicity above 110°. After aging for 1000h at 85°C / 85%RH, the dielectric constant remains at an extremely low level, meeting the requirements of 5G high-frequency signal transmission, and is suitable as a packaging glue in electronic packaging materials. The thermal expansion coefficient can still be maintained at ≤30ppm / °C in a wide temperature range of -40~150°C, and its use in electronic packaging materials can solve the thermal mismatch problem. The water contact angles of Comparative Examples 1 and 2 are low, which limits their use, and the thermal expansion coefficient reaches 65~80ppm / °C under -40~150°C, which makes it easy to crack at high temperatures.

[0073] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the scope defined by the claims.

Claims

1. A silicone-modified acrylic resin, characterized in that: The invention comprises the following components in parts by weight: 40-60 parts of methyl methacrylate, 30-40 parts of butyl acrylate, 3-8 parts of acrylic acid, 10-20 parts of bifunctional silicone monomer, 58-63 parts of solvent, 0.3-0.8 parts of initiator A component, 0.2-0.5 parts of initiator B component, 5-15 parts of fluorine-containing acrylic monomer and 0.1-0.5 parts of epoxy ring-opening catalyst.

2. The organosilicon-modified acrylic resin according to claim 1, characterized in that The structural formula of the bifunctional silicone monomer is CH2=CHCOO-(Si-O)n-CH2CH(O)CH2, wherein n=3~5.

3. The organosilicon-modified acrylic resin according to claim 1, characterized in that The fluorine-containing acrylic monomer is selected from any one of hexafluorobutyl methacrylate and perfluorohexylethyl methacrylate.

4. The organosilicon-modified acrylic resin according to claim 1, characterized in that The epoxy ring-opening catalyst is tetraisopropyl titanate.

5. The organosilicon-modified acrylic resin according to claim 1, characterized in that: The initiator A component is ammonium persulfate, and the initiator B component is ascorbic acid.

6. The organosilicon-modified acrylic resin according to claim 1, characterized in that: The solvent is propylene glycol methyl ether acetate.

7. The method for preparing the organosilicon-modified acrylic resin according to any one of claims 1 to 6, characterized in that: The steps include: Prepolymerization stage: methyl methacrylate, butyl acrylate, acrylic acid, bifunctional silicone monomer and solvent are mixed, heated to a first temperature condition, and aqueous solutions of initiator component A and initiator component B are added dropwise to initiate a free radical polymerization reaction to form a core-shell prepolymer; Chain extension stage: heating to the second temperature condition, adding fluorinated acrylate monomer, and continuing the reaction; Cross-linking stage: heating to the third temperature condition and adding epoxy ring-opening catalyst; Post-processing stage: cooling to the fourth temperature condition, adjusting the pH to 6-7, and filtering to obtain the silicone-modified acrylic resin.

8. The method for preparing the organosilicon-modified acrylic resin according to claim 7, wherein: In the prepolymerization stage, the first temperature condition is 60-70° C., initiating a free radical polymerization reaction for 1-2 hours to form a core-shell prepolymer; In the chain extension stage, the second temperature condition is 80-90°C, fluorinated acrylate monomer is added, and the reaction is continued for 2-3 hours; In the cross-linking stage, the third temperature condition is 110-120° C., an epoxy ring-opening catalyst is added, and the temperature is kept for 2-4 hours; In the post-processing stage, the fourth temperature condition is 40-50°C.

9. Use of the organosilicon-modified acrylic resin according to any one of claims 1 to 6 as a packaging adhesive in electronic packaging materials.

10. Use of the organosilicon-modified acrylic resin according to any one of claims 1 to 6 in film-forming materials.

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