Epoxy resin glue liquid for CEM-1 copper-clad plate and preparation method thereof

Abstract

The present application provides a kind of epoxy resin glue liquid for CEM-1 copper-clad plate, which is made of the following raw materials by mass fraction: brominated epoxy resin 100 parts, HBPDP 6-10 parts, HPNSi 3-6 parts, curing agent 25-28 parts, accelerator 0.2-0.5 parts, synergistic accelerator 0.1-0.3 parts, leveling agent 0.05-0.15 parts, coupling agent 0.3-0.8 parts, auxiliary 4-7 parts, solvent 40-45 parts. The present application also provides a preparation method of the epoxy resin glue liquid for CEM-1 copper-clad plate. The epoxy resin glue liquid for CEM-1 copper-clad plate provided by the present application can effectively improve the bending resistance and flame retardance of CEM-1 copper-clad plate.

Description

Technical Field

[0001] This invention relates to epoxy resin adhesives, and more particularly to an epoxy resin adhesive for CEM-1 copper clad laminates and its preparation method. Background Technology

[0002] Currently, there is a mismatch between the intrinsic properties of general-purpose bisphenol A epoxy resin used in CEM-1 copper-clad laminates and the "paper-based / glass fiber composite, low-pressure rapid lamination" material system of CEM-1. CEM-1 copper-clad laminates are primarily composed of bleached wood pulp paper covered with a thin glass fiber cloth. Their structure exhibits strong anisotropy, high hygroscopicity, and a narrow heat resistance window. During hot pressing, the resin must possess good flow and wetting capabilities at relatively low temperatures to fully penetrate the paper and glass fiber interfaces. Simultaneously, after curing, it must form a sufficiently dense and tough network structure to offset the inconsistencies in thermal expansion and contraction behavior between the paper base, resin, and glass fiber. Unmodified epoxy resins have a relatively rigid molecular structure, concentrated curing shrinkage, and high curing rate and exothermic peak. In the low-heat-resistant paper base system of CEM-1, this can easily lead to localized over-curing or internal stress accumulation, resulting in board warping, interlayer delamination, or brittleness during punching. Furthermore, the flame retardant properties of general-purpose epoxy resins are also unsatisfactory. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide an epoxy resin adhesive for CEM-1 copper clad laminate, which can effectively improve the bending resistance and flame retardant properties of CEM-1 copper clad laminate.

[0004] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0005] An epoxy resin adhesive for CEM-1 copper clad laminate is made from the following raw materials in parts by weight: 100 parts brominated epoxy resin, 6-10 parts HBPDP, 3-6 parts HPNSi, 25-28 parts curing agent, 0.2-0.5 parts accelerator, 0.1-0.3 parts synergistic accelerator, 0.05-0.15 parts leveling agent, 0.3-0.8 parts coupling agent, 4-7 parts additives, and 40-45 parts solvent.

[0006] Furthermore, the bromine content of the brominated epoxy resin described in this invention is 18-21 wt%.

[0007] Furthermore, the HBPDP of the present invention is prepared by the following steps:

[0008] A1. Purge the air from the dry reaction vessel with nitrogen. After adding dichloromethane, cool the system to 0-5°C. Dissolve the pre-dried phenol in dichloromethane. While stirring, slowly add phosphorus oxychloride dropwise, simultaneously adding triethylamine (triethylamine is an acid scavenger; the HCl generated during the reaction is immediately neutralized by triethylamine to form triethylamine salt, thus preventing the system's acidity from increasing and causing side reactions or color deepening). Stir the reaction at below 10°C for 2-3 hours. After the reaction is complete, continue stirring at this temperature for 1-2 hours to obtain the reaction solution. Filter the reaction solution under a nitrogen atmosphere to remove triethylamine. After removing the solvent from the amine salt for 3 hours, a phosphorus oxychloride pre-esterification intermediate was obtained (the success of obtaining the desired phosphorus oxychloride pre-esterification intermediate can be confirmed by detecting the P=O absorption peak and P-Cl characteristic peak by infrared spectroscopy and titrating the chlorine content). The phosphorus oxychloride pre-esterification intermediate obtained in step A1 is a monoester type (O=PCl2(OR)) phosphoryl chloride intermediate, which reduces the excessive reaction and retains two active P-Cl bonds. It can undergo further polycondensation with polyphenols such as bisphenol A or resorcinol, making it suitable for subsequent construction of hyperbranched phosphorus-containing structures.

[0009] A2. Purge the dry reaction vessel with nitrogen to replace air, add dichloromethane, bisphenol A, and resorcinol, heat to 40-45℃ until completely dissolved, then add triethylamine to form an alkaline mixture. Subsequently, add the phosphorus oxychloride pre-esterification intermediate obtained in step A1 dropwise to the alkaline mixture at 0-5℃ (the HCl generated during the dropwise addition is captured by the triethylamine to form a triethylamine salt precipitate). Control the system temperature to not exceed 10℃. After the dropwise addition is complete, heat to 45-50℃ and maintain this temperature for 3-4 hours. The reaction is carried out for 1 hour (to allow the esterification reaction to proceed fully and gradually form a hyperbranched structure), then heated to 65℃ and reacted for another hour (to promote the complete conversion of residual P-Cl; the endpoint is determined by the disappearance of the infrared absorption peak of P-Cl detected by online sampling). After the reaction is completed, the temperature is lowered to 30℃ to obtain the reaction solution. The reaction solution is filtered to remove triethylamine salt to obtain the filtrate. The filtrate is distilled under reduced pressure at 60-70℃ to recover the solvent. The temperature is raised to 110-120℃ and the residual solvent and low molecular weight byproducts are removed under a vacuum of -0.09MPa to obtain HBPDP (the final viscosity (25℃) is controlled to be 8000-15000mPa·s, the acid value is less than 1mgKOH / g, and the residual P-Cl content is less than 0.05%).

[0010] Further, in step A1 of the preparation of HBPDP described in this invention, the mass ratio of dichloromethane to phosphorus oxychloride is 1:2.5, and the molar ratio of phosphorus oxychloride, phenol, and triethylamine is 1:1.01:1.1; the solvent removal process is as follows: solvent removal begins at a reactor temperature of 25-30℃ and a pressure of 20-30kPa, and then the vacuum degree is increased to 5-15kPa and the reactor temperature is increased to 35-39℃;

[0011] In step A2 of the preparation of HBPDP, by mass parts, there are 120-150 parts of dichloromethane, 34-38 parts of bisphenol A, 8-12 parts of resorcinol, 22-25 parts of triethylamine, and 38-42 parts of the phosphorus oxychloride pre-esterification intermediate obtained in step A1.

[0012] HPNSi was prepared using γ-aminopropyltriethoxysilane and γ-aminoethylaminopropyltrimethoxysilane as the main silicon sources. DOPO-epoxy addition monomers were introduced, allowing them to undergo partial alcoholysis with Si-OR during polycondensation via PO₄²⁻, while simultaneously forming hydrogen-bonded complexes with amines to prevent the precipitation of free low-molecular-weight monomers. The amine component consisted of a combination of diethylenetriamine and a small amount of triethylenetetramine to ensure a branching degree of 0.45-0.55. Xylene and a trace amount of deionized water were used as solvents, with zinc acetate added as a weak complexation inhibitor to prevent excessive glass transition crosslinking.

[0013] Specifically, the HPNSi described in this invention is prepared by the following steps:

[0014] B1. Add DOPO and ethanol to a reaction flask, heat to 125℃ and stir for 20-30 minutes to obtain a DOPO solution. Add ethylene glycol diglycidyl ether dropwise to the DOPO solution, heat to 150℃ and react for 5-6 hours to obtain a reaction solution. Cool the reaction solution to room temperature and filter to obtain a filter cake. Wash the filter cake three times with ethanol and vacuum dry for 12 hours to obtain a phosphorus-containing monomer.

[0015] B2. Under nitrogen protection, the amine component composed of diethylenetriamine and triethylenetetramine is added to xylene and stirred at 45°C until uniformly mixed to obtain the amine phase. The silane component composed of γ-aminopropyltriethoxysilane and γ-aminoethylaminopropyltrimethoxysilane is added dropwise at 60-65°C. After the dropwise addition is completed, the temperature is raised to 80-85°C and the phosphorus-containing monomer obtained in step B1 is added (to enable it to react synergistically with the residual Si-OR). Then the temperature is raised to 90°C, and deionized water is added (to trigger limited hydrolysis condensation) and zinc acetate (to complex and inhibit long-range condensation). The reaction is then kept at this temperature for 2 hours (to complete the branching structure shaping) to obtain the reaction solution. The reaction solution is heated to 110-115°C and the alcohol by-products and solvent are removed under reduced pressure to obtain HPNSi (the reaction endpoint can be determined by online viscosity and infrared monitoring of the Si-OR absorption peak decay rate. The endpoint viscosity is controlled at 6000-9000 mPa·s, the free amine content is less than 0.4%, and no gel particles are ensured).

[0016] Furthermore, in step B1 of the preparation of HPNSi described in this invention, the ratio of DOPO, ethanol, and ethylene glycol diglycidyl ether during the reaction is 0.2 mol: 150 mL: 0.1 mol, and the vacuum drying temperature is 80 °C.

[0017] In step B2 of the preparation of HPNSi, by mass fraction, the amine component is 12-15 parts, xylene is 15-18 parts, silane component is 58-62 parts, phosphorus-containing monomer obtained in step B1 is 8-12 parts, deionized water is 0.35-0.5 parts, zinc acetate is 0.05-0.08 parts, the molar ratio of diethylenetriamine to triethylenetetramine in the amine component is 7:3, the molar ratio of γ-aminopropyltriethoxysilane to γ-aminoethylaminopropyltrimethoxysilane in the silane component is 17:3, and the dropping time of the silane component is 2.5 hours.

[0018] Furthermore, the curing agent of the present invention is a linear phenolic resin with a softening point of 85-105℃, the accelerator is 2-methylimidazole, and the synergistic accelerator is DMP-30 or BDMA.

[0019] Furthermore, the leveling agent of the present invention is BYK-150, the coupling agent is KH-550, the auxiliary agent is tetramethylfluorourea hexafluorophosphate, and the solvent is composed of equal masses of ethanol and acetone.

[0020] Another technical problem to be solved by the present invention is to provide a method for preparing the epoxy resin solution for the above-mentioned CEM-1 copper clad laminate.

[0021] To solve the above technical problems, the technical solution is as follows:

[0022] A method for preparing an epoxy resin adhesive for CEM-1 copper clad laminate includes the following steps:

[0023] S1. Weigh each raw material according to the mass fraction, dissolve HBPDP in brominated epoxy resin, then add HPNSi, and stir at 80℃ for 30-40 minutes to obtain modified resin.

[0024] S2. Add the solvent to the reaction vessel, heat it to 50-60℃, and then add the modified resin obtained in step S1 while stirring. Stir until it is completely dissolved to obtain a resin solution.

[0025] S3. Cool the resin solution obtained in step S2 to 45-55℃, add the curing agent and continue stirring until completely dissolved to obtain the epoxy-phenolic system.

[0026] S4. Cool the epoxy-phenolic system obtained in step S3 to 40-50℃, add accelerator, synergist, leveling agent, coupling agent and additive, and continue stirring for 30-60 minutes to obtain a mixture. Filter the mixture to remove gel particles and let it stand for 4-12 hours (to make the system reach a stable molecular distribution and impregnation suitability) to obtain CEM-1 epoxy resin solution for copper clad laminate.

[0027] Furthermore, in step S4 of the present invention, the mesh size of the filter is 100-200 mesh.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] (1) The HPNSi used in this invention has a phosphorus content of about 2.0-3.0 wt% and a silicon content of about 10-12 wt%, which can significantly shorten the afterflame time in the UL94 vertical combustion test, enhance the continuity of the char layer, and reduce the delamination ratio after thermal shock. Since the phosphorus component participates in the carbonization catalysis, the char layer structure presents a dual-layer protection mechanism of "silicon-oxygen skeleton support + phosphate dense layer coverage", which can maintain interface stability even under dual 85 aging conditions.

[0030] (2) The HBPDP and HPNSi used in this invention are hyperbranched polymers with unique macromolecular structures, low viscosity, no entanglement, and abundant functional groups. They are suitable for epoxy resin blending systems, which can promote the curing reaction of the resin system, improve the flexibility of the cross-linking network of the blending system, alleviate the stress concentration at the interface, and thus improve the bending and fatigue resistance of CEM-1 copper clad laminate. At the same time, it can also reduce the curing temperature, improve the board bending that may occur during the pressing process, enhance the flame retardant effect, and reduce smoke generation. In addition, the additive used in this invention—tetramethylfluorourea hexafluorophosphate—can also effectively improve the bonding strength and solderability of CEM-1 copper clad laminate.

[0031] (3) This invention limits the dosage range of HBPDP and HPNSi. Within this range, both a phosphorus-catalyzed carbonization layer and an inorganic framework support layer can be constructed from silicon-nitrogen branched structures, avoiding the brittleness of a single phosphorus-based carbon layer. Experiments show that when the dosage of HBPDP is too low, the condensed phase carbonization catalysis is insufficient, and the improvement of UL94 afterflame time is limited; when the dosage of HBPDP is too high, the polarity of the system increases significantly, the water absorption rate increases, the dielectric constant increases, and the Tg decreases significantly; when the dosage of HPNSi is too low, the improvement of Z-direction CTE is not significant; when the dosage of HPNSi is too high, the lamination flow window may be narrowed due to the high proportion of silicon-oxygen phase, and the flowability of the prepreg may decrease. Detailed Implementation

[0032] The present invention will now be described in detail with reference to specific embodiments. The illustrative embodiments and descriptions of the present invention are used to explain the present invention, but are not intended to limit the present invention.

[0033] Example 1

[0034] CEM-1 epoxy resin adhesive for copper clad laminates is made from the following raw materials in parts by weight: 100 parts brominated epoxy resin, 8 parts HBPDP, 5 parts HPNSi, 27 parts curing agent, 0.4 parts accelerator, 0.2 parts synergistic accelerator, 0.1 parts leveling agent, 0.6 parts coupling agent, 6 parts additives, and 44 parts solvent. The brominated epoxy resin has a bromine content of 20 wt%, the curing agent is a linear phenolic resin with a softening point of 100℃, the accelerator is 2-methylimidazole, the synergistic accelerator is DMP-30, the leveling agent is BYK-150, the coupling agent is KH-550, the additive is tetramethylfluorourea hexafluorophosphate, and the solvent consists of equal masses of ethanol and acetone.

[0035] HBPDP is made by the following steps:

[0036] A1. The dry reaction vessel was purged with nitrogen to replace the air. After adding dichloromethane, the system was cooled to 2°C. The pre-dried phenol was dissolved in dichloromethane. Phosphorus oxychloride was slowly added dropwise while stirring. The mass ratio of dichloromethane to phosphorus oxychloride was 1:2.5. Triethylamine was added simultaneously. The molar ratio of phosphorus oxychloride, phenol, and triethylamine was 1:1.01:1.1. The reaction was stirred at below 10°C for 2.5 hours. After the reaction was completed, the mixture was kept at the same temperature and stirred for another 1.5 hours to obtain the reaction solution. The reaction solution was filtered under a nitrogen atmosphere to remove the triethylamine salt. After removing the solvent for 3 hours, the pre-esterified intermediate of phosphorus oxychloride was obtained. The solvent removal process was as follows: the solvent removal was started at a vessel temperature of 28°C and a pressure of 25 kPa. Then the vacuum degree was increased to 10 kPa and the vessel temperature was increased to 37°C.

[0037] A2. Purge the dry reaction vessel with nitrogen to replace air, add dichloromethane, bisphenol A, and resorcinol, heat to 42℃ until completely dissolved, then add triethylamine to form an alkaline mixture. Subsequently, add the phosphorus oxychloride pre-esterification intermediate obtained in step A1 dropwise to the alkaline mixture at 2℃, controlling the system temperature to not exceed 10℃. After the addition is complete, heat to 48℃ and hold for 3.5 hours, then heat to 65℃ and react for another hour. After the reaction is complete, cool to 30℃ to obtain the reaction solution. Filter the reaction solution to remove the triethylamine salt and obtain the filtrate. Distill the filtrate under reduced pressure at 65℃ to recover the solvent. Heat to 115℃ and remove residual solvent and low-molecular-weight byproducts under a vacuum of -0.09MPa to obtain HBPDP (controlling the final viscosity (25℃) to 12000 mPa·s, acid value less than 1 mg KOH / g, residual P-Cl content less than 0.05%). By mass, 135 parts dichloromethane, bisphenol A... 36 parts, resorcinol 10 parts, triethylamine 24 parts, and 40 parts of the phosphorus oxychloride pre-esterification intermediate obtained in step A1.

[0038] HPNSi is made by the following steps:

[0039] B1. Add DOPO and ethanol to a reaction flask, heat to 125℃ and stir for 25 minutes to obtain a DOPO solution. Add ethylene glycol diglycidyl ether dropwise to the DOPO solution. The ratio of DOPO, ethanol and ethylene glycol diglycidyl ether during the reaction is 0.2 mol: 150 mL: 0.1 mol. Heat to 150℃ and react for 5.5 hours to obtain a reaction solution. Cool the reaction solution to room temperature and filter to obtain a filter cake. Wash the filter cake three times with ethanol and dry it under vacuum at 80℃ for 12 hours to obtain a phosphorus-containing monomer.

[0040] B2. Under nitrogen protection, an amine component consisting of diethylenetriamine and triethylenetetramine in a molar ratio of 7:3 was added to xylene. The mixture was stirred at 45°C until homogeneous to obtain the amine phase. A silane component consisting of γ-aminopropyltriethoxysilane and γ-aminoethylaminopropyltrimethoxysilane in a molar ratio of 17:3 was then added dropwise at 63°C over 2.5 hours. After the addition was complete, the temperature was raised to 83°C, and the phosphorus-containing monomer obtained in step B1 was added. The temperature was then raised to 90°C, and deionized water and zinc acetate were added. The reaction was then maintained at this temperature for 2 hours. The reaction solution was obtained after hours. The reaction solution was heated to 113℃ and the alcohol by-products and solvent were removed under reduced pressure to obtain HPNSi (the reaction endpoint can be determined by online viscosity and infrared monitoring of the Si-OR absorption peak decay rate. The endpoint viscosity was controlled at 8000 mPa·s, the free amine content was less than 0.4%, and no gel particles were ensured). By mass fraction, the amine component was 14 parts, xylene was 17 parts, silane component was 60 parts, phosphorus-containing monomer obtained in step B1 was 10 parts, deionized water was 0.45 parts, and zinc acetate was 0.07 parts.

[0041] The preparation method of Example 1 includes the following steps:

[0042] S1. Weigh each raw material according to the mass fraction, dissolve HBPDP in brominated epoxy resin, then add HPNSi, and stir at 80°C for 35 minutes to obtain modified resin.

[0043] S2. Add the solvent to the reaction vessel, heat to 50°C, and then add the modified resin obtained in step S1 while stirring. Stir until completely dissolved to obtain a resin solution.

[0044] S3. Cool the resin solution obtained in step S2 to 50°C, add the curing agent and continue stirring until completely dissolved to obtain the epoxy-phenolic system;

[0045] S4. Cool the epoxy-phenolic system obtained in step S3 to 45°C, add accelerator, synergist, leveling agent, coupling agent and additive, and continue stirring for 45 minutes to obtain a mixture. Filter the mixture through a 200-mesh filter to remove gel particles and let it stand for 8 hours to obtain CEM-1 epoxy resin adhesive for copper clad laminate.

[0046] Example 2

[0047] CEM-1 epoxy resin adhesive for copper clad laminates is made from the following raw materials in parts by weight: 100 parts brominated epoxy resin, 6 parts HBPDP, 3 parts HPNSi, 25 parts curing agent, 0.2 parts accelerator, 0.1 parts synergistic accelerator, 0.05 parts leveling agent, 0.3 parts coupling agent, 4 parts additives, and 40 parts solvent. The brominated epoxy resin has a bromine content of 18 wt%, the curing agent is a linear phenolic resin with a softening point of 85℃, the accelerator is 2-methylimidazole, the synergistic accelerator is BDMA, the leveling agent is BYK-150, the coupling agent is KH-550, the additive is tetramethylfluorourea hexafluorophosphate, and the solvent consists of equal masses of ethanol and acetone.

[0048] HBPDP is made by the following steps:

[0049] A1. Purge the air from the dry reaction vessel with nitrogen, add dichloromethane, and cool the system to 0°C. Dissolve the pre-dried phenol in dichloromethane, and slowly add phosphorus oxychloride dropwise while stirring. The mass ratio of dichloromethane to phosphorus oxychloride is 1:2.5. Simultaneously add triethylamine. The molar ratio of phosphorus oxychloride, phenol, and triethylamine is 1:1.01:1.1. Stir the reaction at below 10°C for 3 hours. After the reaction is complete, continue stirring at the same temperature for 2 hours to obtain the reaction solution. Filter the reaction solution under a nitrogen atmosphere to remove the triethylamine salt. After removing the solvent for 3 hours, obtain the phosphorus oxychloride pre-esterified intermediate. The solvent removal process is as follows: start solvent removal at a vessel temperature of 25°C and a pressure of 30 kPa, then increase the vacuum to 15 kPa and the vessel temperature to 35°C.

[0050] A2. Purge the dry reaction vessel with nitrogen to replace air, add dichloromethane, bisphenol A, and resorcinol, heat to 40℃ until completely dissolved, then add triethylamine to form an alkaline mixture. Subsequently, add the phosphorus oxychloride pre-esterification intermediate obtained in step A1 dropwise to the alkaline mixture at 0℃, controlling the system temperature to not exceed 10℃. After the addition is complete, heat to 45℃ and hold for 4 hours, then heat to 65℃ and react for another hour. After the reaction is complete, cool to 30℃ to obtain the reaction solution. Filter the reaction solution to remove the triethylamine salt and obtain the filtrate. Distill the filtrate under reduced pressure at 60℃ to recover the solvent. Heat to 110℃ and remove residual solvent and low-molecular-weight byproducts under a vacuum of -0.09MPa to obtain HBPDP (controlling the final viscosity (25℃) to 8000 mPa·s, acid value less than 1 mg KOH / g, and residual P-Cl content less than 0.05%). By mass, 120 parts dichloromethane, bisphenol A... 34 parts, resorcinol 8 parts, triethylamine 22 parts, and 38 parts of the phosphorus oxychloride pre-esterification intermediate obtained in step A1.

[0051] HPNSi is made by the following steps:

[0052] B1. Add DOPO and ethanol to a reaction flask, heat to 125℃ and stir for 30 minutes to obtain a DOPO solution. Add ethylene glycol diglycidyl ether dropwise to the DOPO solution. The ratio of DOPO, ethanol and ethylene glycol diglycidyl ether during the reaction is 0.2 mol: 150 mL: 0.1 mol. Heat to 150℃ and react for 6 hours to obtain a reaction solution. Cool the reaction solution to room temperature and filter to obtain a filter cake. Wash the filter cake three times with ethanol and dry it under vacuum at 80℃ for 12 hours to obtain a phosphorus-containing monomer.

[0053] B2. Under nitrogen protection, an amine component consisting of diethylenetriamine and triethylenetetramine in a molar ratio of 7:3 was added to xylene. The mixture was stirred at 45°C until homogeneous to obtain the amine phase. A silane component consisting of γ-aminopropyltriethoxysilane and γ-aminoethylaminopropyltrimethoxysilane in a molar ratio of 17:3 was then added dropwise at 60°C over 2.5 hours. After the addition was complete, the temperature was raised to 80°C, and the phosphorus-containing monomer obtained in step B1 was added. The temperature was then raised to 90°C, and deionized water and zinc acetate were added. The reaction was then maintained at this temperature for 2 hours. The reaction solution was obtained after hours. The reaction solution was heated to 110℃ and the alcohol by-products and solvent were removed under reduced pressure to obtain HPNSi (the reaction endpoint can be determined by online viscosity and infrared monitoring of the Si-OR absorption peak decay rate. The endpoint viscosity was controlled at 6000 mPa·s, the free amine content was less than 0.4%, and no gel particles were ensured). By mass fraction, the amine component was 12 parts, xylene was 15 parts, silane component was 58 parts, phosphorus-containing monomer obtained in step B1 was 8 parts, deionized water was 0.35 parts, and zinc acetate was 0.05 parts.

[0054] The preparation method of Example 2 includes the following steps:

[0055] S1. Weigh each raw material according to the mass fraction, dissolve HBPDP in brominated epoxy resin, then add HPNSi, and stir at 80°C for 40 minutes to obtain modified resin.

[0056] S2. Add the solvent to the reaction vessel, heat it to 40°C, and then add the modified resin obtained in step S1 while stirring. Stir until completely dissolved to obtain a resin solution.

[0057] S3. Cool the resin solution obtained in step S2 to 45°C, add the curing agent and continue stirring until completely dissolved to obtain the epoxy-phenolic system;

[0058] S4. Cool the epoxy-phenolic system obtained in step S3 to 40°C, add accelerator, synergist, leveling agent, coupling agent and additive, and continue stirring for 60 minutes to obtain a mixture. Filter the mixture through a 100-mesh filter to remove gel particles and let it stand for 12 hours to obtain CEM-1 epoxy resin solution for copper clad laminate.

[0059] Example 3

[0060] CEM-1 epoxy resin adhesive for copper clad laminates is made from the following raw materials in parts by weight: 100 parts brominated epoxy resin, 10 parts HBPDP, 6 parts HPNSi, 28 parts curing agent, 0.5 parts accelerator, 0.3 parts synergistic accelerator, 0.15 parts leveling agent, 0.8 parts coupling agent, 7 parts additives, and 45 parts solvent. The brominated epoxy resin has a bromine content of 21 wt%, the curing agent is a linear phenolic resin with a softening point of 105℃, the accelerator is 2-methylimidazole, the synergistic accelerator is DMP-30, the leveling agent is BYK-150, the coupling agent is KH-550, the additive is tetramethylfluorourea hexafluorophosphate, and the solvent consists of equal masses of ethanol and acetone.

[0061] HBPDP is made by the following steps:

[0062] A1. Purge the air from the dry reaction vessel with nitrogen, add dichloromethane, and cool the system to 5°C. Dissolve the pre-dried phenol in dichloromethane, and slowly add phosphorus oxychloride dropwise while stirring. The mass ratio of dichloromethane to phosphorus oxychloride is 1:2.5. Simultaneously add triethylamine. The molar ratio of phosphorus oxychloride, phenol, and triethylamine is 1:1.01:1.1. Stir the reaction at below 10°C for 2 hours. After the reaction is complete, continue stirring at the same temperature for 1 hour to obtain the reaction solution. Filter the reaction solution under a nitrogen atmosphere to remove the triethylamine salt. After removing the solvent for 3 hours, obtain the phosphorus oxychloride pre-esterified intermediate. The solvent removal process is as follows: start solvent removal at a vessel temperature of 30°C and a pressure of 20 kPa, then increase the vacuum to 5 kPa and the vessel temperature to 39°C.

[0063] A2. Purge the dry reaction vessel with nitrogen to replace air, add dichloromethane, bisphenol A, and resorcinol, heat to 45°C until completely dissolved, then add triethylamine to form an alkaline mixture. Subsequently, add the phosphorus oxychloride pre-esterification intermediate obtained in step A1 dropwise to the alkaline mixture at 5°C, controlling the system temperature to not exceed 10°C. After the addition is complete, heat to 50°C and hold for 3 hours, then heat to 65°C and react for another hour. After the reaction is complete, cool to 30°C to obtain the reaction solution. Filter the reaction solution to remove the triethylamine salt and obtain the filtrate. Distill the filtrate under reduced pressure at 70°C to recover the solvent. Heat to 120°C and remove residual solvent and low-molecular-weight byproducts under a vacuum of -0.09 MPa to obtain HBPDP (controlling the final viscosity (25°C) to 15000 mPa·s, acid value less than 1 mg KOH / g, and residual P-Cl content less than 0.05%). By mass, 150 parts dichloromethane, bisphenol A... 38 parts, resorcinol 12 parts, triethylamine 25 parts, and 42 parts of the phosphorus oxychloride pre-esterification intermediate obtained in step A1.

[0064] HPNSi is made by the following steps:

[0065] B1. Add DOPO and ethanol to a reaction flask, heat to 125℃ and stir for 20 minutes to obtain a DOPO solution. Add ethylene glycol diglycidyl ether dropwise to the DOPO solution. The ratio of DOPO, ethanol and ethylene glycol diglycidyl ether during the reaction is 0.2 mol: 150 mL: 0.1 mol. Heat to 150℃ and react for 5 hours to obtain a reaction solution. Cool the reaction solution to room temperature and filter to obtain a filter cake. Wash the filter cake three times with ethanol and dry it under vacuum at 80℃ for 12 hours to obtain a phosphorus-containing monomer.

[0066] B2. Under nitrogen protection, an amine component consisting of diethylenetriamine and triethylenetetramine in a molar ratio of 7:3 was added to xylene. The mixture was stirred at 45°C until homogeneous to obtain the amine phase. A silane component consisting of γ-aminopropyltriethoxysilane and γ-aminoethylaminopropyltrimethoxysilane in a molar ratio of 17:3 was then added dropwise at 65°C over 2.5 hours. After the addition was complete, the temperature was raised to 85°C, and the phosphorus-containing monomer obtained in step B1 was added. The temperature was then raised to 90°C, and deionized water and zinc acetate were added. The reaction was then maintained at this temperature for 2 hours. The reaction solution was obtained after hours. The reaction solution was heated to 115℃ and the alcohol by-products and solvent were removed under reduced pressure to obtain HPNSi (the reaction endpoint can be determined by online viscosity and infrared monitoring of the Si-OR absorption peak decay rate. The endpoint viscosity was controlled at 9000 mPa·s, the free amine content was less than 0.4%, and no gel particles were ensured). By mass fraction, the amine component was 15 parts, xylene was 18 parts, silane component was 62 parts, phosphorus-containing monomer obtained in step B1 was 12 parts, deionized water was 0.5 parts, and zinc acetate was 0.08 parts.

[0067] The preparation method of Example 3 includes the following steps:

[0068] S1. Weigh each raw material according to the mass fraction, dissolve HBPDP in brominated epoxy resin, then add HPNSi, and stir at 80°C for 30 minutes to obtain modified resin.

[0069] S2. Add the solvent to the reaction vessel, heat to 60°C, and then add the modified resin obtained in step S1 while stirring. Stir until completely dissolved to obtain a resin solution.

[0070] S3. Cool the resin solution obtained in step S2 to 55°C, add the curing agent and continue stirring until completely dissolved to obtain the epoxy-phenolic system;

[0071] S4. Cool the epoxy-phenolic system obtained in step S3 to 50°C, add accelerator, synergist, leveling agent, coupling agent and additive, and continue stirring for 30 minutes to obtain a mixture. Filter the mixture through a 200-mesh filter to remove gel particles and let it stand for 4 hours to obtain CEM-1 epoxy resin solution for copper clad laminate.

[0072] Comparative Example 1

[0073] Unlike Example 1, the raw materials do not include HBPDP and HPNSi, and the preparation steps of HBPDP and HPNSi are omitted.

[0074] Comparative Example 2

[0075] Unlike Example 1, HBPDP is not included in the raw materials, and the preparation step of HBPDP is omitted.

[0076] Comparative Example 3

[0077] The difference from Example 1 is that HPNSi is not included in the raw materials, and the preparation step of HPNSi is omitted.

[0078] Comparative Example 4

[0079] The difference from Example 1 is that the raw materials do not include the auxiliary agent tetramethylfluorourea hexafluorophosphate.

[0080] Experimental Example 1:

[0081] To manufacture CEM-1 copper clad laminate, follow these steps:

[0082] (1) Place the CEM-1 copper clad laminate with epoxy resin solution (prepared from Examples 1-3 and Comparative Examples 1-4) in a horizontal gluing machine, place the bleached wood pulp paper (126g / m²) in the horizontal gluing machine and apply the glue for 2 minutes at a time, then send it into the oven and bake at 150°C for 2 minutes to obtain the core material semi-cured sheet.

[0083] (2) Place the CEM-1 copper clad laminate with epoxy resin solution (prepared from Examples 1-3 and Comparative Examples 1-4) in a horizontal gluing machine, place the fiberglass cloth (7628 type) in the horizontal gluing machine and apply the glue for 2 minutes at a time, then send it into the oven and bake at 150°C for 2 minutes to obtain a fabric semi-cured sheet.

[0084] (3) Take 5 core material semi-cured sheets obtained in step (1) and stack them together to obtain laminate one. Cover the upper and lower surfaces of laminate one with a fabric semi-cured sheet obtained in step (2) to obtain laminate two. Cover the upper surface of laminate two with a copper foil (thickness of 18μm, conforming to IPC-MF-150F standard) to obtain laminate three. Place laminate three between two stainless steel plates and send it into a laminator. Hot press at 170℃ and 30MPa pressure for 1.5 hours. After cooling to room temperature, obtain CEM-1 copper clad laminate.

[0085] Experiment Example 2: Flame Retardant Performance Test

[0086] Test reference standard / method: UL-94 standard.

[0087] Testing instrument: Horizontal and vertical combustion tester.

[0088] Test object and target: The flame retardancy rating of the CEM-1 copper clad laminate (Examples 1-3) prepared by Experiment 1.

[0089] The test results are shown in Table 1:

[0090] Flame retardant rating Example 1 V-0 Example 2 V-0 Example 3 V-0

[0091] Table 1

[0092] As can be seen from Table 1, the flame retardant ratings of Examples 1-4 of the present invention all reached the V-0 level, indicating that the epoxy resin adhesive for CEM-1 copper clad laminate prepared by the present invention can effectively improve the flame retardant performance of CEM-1 copper clad laminate.

[0093] Experiment Example 3: Bending Performance Test

[0094] Test reference standard / method: IPC-TM-650 standard.

[0095] Testing instrument: Universal testing machine.

[0096] Test object and objective: The bending strength of the CEM-1 copper clad laminates (Examples 1-3 and Comparative Examples 1-3) prepared by Experiment 1.

[0097] Higher bending strength indicates better bending resistance. The test results are shown in Table 2.

[0098] Bending strength (MPa) Example 1 530 Example 2 528 Example 3 534 Comparative Example 1 485 Comparative Example 2 509 Comparative Example 3 512

[0099] Table 2

[0100] As shown in Table 2, the bending strength of Examples 1-4 of the present invention is higher than that of Comparative Example 1, indicating that the epoxy resin adhesive for CEM-1 copper clad laminate prepared by the present invention can effectively improve the bending resistance of CEM-1 copper clad laminate. Comparative Examples 2 and 3 use some different raw materials and preparation steps than Example 1. Compared with Example 1, the bending strength of Comparative Examples 2 and 3 is lower, indicating that HBPDP and HPNSi used in the present invention can effectively improve the bending resistance of CEM-1 copper clad laminate.

[0101] Experiment Example 4: Smoke Suppression Performance Test

[0102] Test reference standard / method: ISO 5660-1 Cone calorimetry test method.

[0103] Testing instrument: cone calorimeter.

[0104] Test subject and objective: The total smoke production of the CEM-1 copper clad laminates (Examples 1-3, Comparative Examples 1-3) prepared in Experiment 1.

[0105] A lower total smoke production indicates better smoke suppression performance. The test results are shown in Table 3.

[0106] Total tobacco production (m²) Example 1 8.58 Example 2 8.96 Example 3 8.31 Comparative Example 1 19.54 Comparative Example 2 13.27 Comparative Example 3 13.59

[0107] Table 3

[0108] As shown in Table 3, the total smoke production of Examples 1-4 of the present invention is lower than that of Comparative Example 1, indicating that the epoxy resin adhesive for CEM-1 copper clad laminate prepared by the present invention can effectively improve the smoke suppression performance of CEM-1 copper clad laminate. Comparative Examples 2 and 3 use some different raw materials and preparation steps than Example 1. Compared with Example 1, the total smoke production of Comparative Examples 2 and 3 has increased, indicating that HBPDP and HPNSi used in the present invention can effectively improve the smoke suppression performance of CEM-1 copper clad laminate.

[0109] Experiment Example 5: Bonding Strength Test

[0110] Test reference standard / method: IPC-TM-650 standard.

[0111] Testing instrument: Peel strength tester.

[0112] Test object and target: Peel strength of CEM-1 copper clad laminates (Examples 1-3, Comparative Example 4) prepared by Experiment 1.

[0113] Higher peel strength indicates better adhesion. The test results are shown in Table 4.

[0114] Peel strength (KN / m) Example 1 1.53 Example 2 1.47 Example 3 1.55 Comparative Example 4 1.28

[0115] Table 4

[0116] As shown in Table 4, the peel strength of Examples 1-4 of the present invention is relatively high, indicating that the epoxy resin adhesive for CEM-1 copper clad laminate prepared by the present invention can effectively improve the adhesion of CEM-1 copper clad laminate. Comparative Example 4 uses some different raw materials and preparation steps than Example 1. Compared with Example 1, the peel strength of Comparative Example 4 is lower, indicating that the additive used in the present invention—tetramethylfluorourea hexafluorophosphate—can effectively improve the adhesion of CEM-1 copper clad laminate.

[0117] Experiment Example 6: Solderability Test

[0118] Test method: Immerse the CEM-1 copper-clad laminate in a solder bath at 288°C and record the time elapsed from the start of immersion to the appearance of blistering or cracking of the copper foil. This time is recorded as the solder immersion resistance time.

[0119] Test object and target: The soldering resistance time of the CEM-1 copper clad laminate (Examples 1-3, Comparative Example 4) prepared by Experiment 1.

[0120] A longer immersion solderability time indicates better immersion solderability. The test results are shown in Table 5:

[0121] Dip-in soldering time (s) Example 1 59 Example 2 54 Example 3 61 Comparative Example 4 48

[0122] Table 5

[0123] As shown in Table 5, the solder immersion resistance times of Examples 1-4 of the present invention are all relatively long, indicating that the epoxy resin adhesive for CEM-1 copper clad laminates prepared by the present invention can effectively improve the solder immersion resistance of CEM-1 copper clad laminates. Comparative Example 4 uses some different raw materials and preparation steps than Example 1. Compared with Example 1, the solder immersion resistance time of Comparative Example 4 is shorter, indicating that the additive used in the present invention—tetramethylfluorourea hexafluorophosphate—can effectively improve the solder immersion resistance of CEM-1 copper clad laminates.

[0124] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. An epoxy resin adhesive for CEM-1 copper clad laminates, characterized in that: It is made from the following raw materials in parts by weight: 100 parts brominated epoxy resin, 6-10 parts HBPDP, 3-6 parts HPNSi, 25-28 parts curing agent, 0.2-0.5 parts accelerator, 0.1-0.3 parts synergistic accelerator, 0.05-0.15 parts leveling agent, 0.3-0.8 parts coupling agent, 4-7 parts additives, and 40-45 parts solvent.

2. The epoxy resin adhesive for CEM-1 copper clad laminate according to claim 1, characterized in that: The bromine content of the brominated epoxy resin is 18-21 wt%.

3. The epoxy resin adhesive for CEM-1 copper clad laminate according to claim 1, characterized in that: The HBPDP is prepared by the following steps: A1. Purge the dry reaction vessel with nitrogen to replace the air, add dichloromethane and cool the system to 0-5℃, dissolve the pre-dried phenol in dichloromethane, slowly add phosphorus oxychloride dropwise while stirring, and add triethylamine at the same time. Stir the reaction at below 10℃ for 2-3 hours. After the reaction is complete, continue to keep warm and stir for 1-2 hours to obtain the reaction solution. Filter the reaction solution under nitrogen atmosphere to remove the triethylamine salt. After removing the solvent for 3 hours, obtain the phosphorus oxychloride pre-esterified intermediate. A2. Purge the dry reaction vessel with nitrogen to replace the air, add dichloromethane, bisphenol A, and resorcinol, heat to 40-45℃ until completely dissolved, then add triethylamine to form an alkaline mixture. Subsequently, add the phosphorus oxychloride pre-esterification intermediate obtained in step A1 dropwise to the alkaline mixture at 0-5℃, controlling the system temperature to not exceed 10℃. After the dropwise addition is complete, heat to 45-50℃ and hold for 3-4 hours, then heat to 65℃ and react for another hour. After the reaction is complete, cool to 30℃ to obtain the reaction solution. Filter the reaction solution to remove the triethylamine salt and obtain the filtrate. Distill the filtrate under reduced pressure at 60-70℃ to recover the solvent. Heat to 110-120℃ and remove the residual solvent and low-molecular-weight byproducts under a vacuum of -0.09MPa to obtain HBPDP.

4. The epoxy resin adhesive for CEM-1 copper clad laminate according to claim 3, characterized in that: In step A1 of the preparation of HBPDP, the mass ratio of dichloromethane to phosphorus oxychloride is 1:2.5, and the molar ratio of phosphorus oxychloride, phenol, and triethylamine is 1:1.01:1.

1. The solvent removal process is as follows: solvent removal begins at a reactor temperature of 25-30℃ and a pressure of 20-30kPa, and then the vacuum degree is increased to 5-15kPa and the reactor temperature is increased to 35-39℃. In step A2 of the preparation of HBPDP, by mass parts, there are 120-150 parts of dichloromethane, 34-38 parts of bisphenol A, 8-12 parts of resorcinol, 22-25 parts of triethylamine, and 38-42 parts of the phosphorus oxychloride pre-esterification intermediate obtained in step A1.

5. The epoxy resin adhesive for CEM-1 copper clad laminate according to claim 1, characterized in that: The HPNSi is made by the following steps: B1. Add DOPO and ethanol to a reaction flask, heat to 125℃ and stir for 20-30 minutes to obtain a DOPO solution. Add ethylene glycol diglycidyl ether dropwise to the DOPO solution, heat to 150℃ and react for 5-6 hours to obtain a reaction solution. Cool the reaction solution to room temperature and filter to obtain a filter cake. Wash the filter cake three times with ethanol and vacuum dry for 12 hours to obtain a phosphorus-containing monomer. B2. Under nitrogen protection, the amine component consisting of diethylenetriamine and triethylenetetramine is added to xylene and stirred at 45°C until homogeneous to obtain the amine phase. The silane component consisting of γ-aminopropyltriethoxysilane and γ-aminoethylaminopropyltrimethoxysilane is added dropwise at 60-65°C. After the dropwise addition is complete, the temperature is raised to 80-85°C and the phosphorus-containing monomer obtained in step B1 is added. Then the temperature is raised to 90°C, deionized water and zinc acetate are added, and the reaction is maintained for 2 hours to obtain the reaction solution. The reaction solution is heated to 110-115°C and the alcohol byproducts and solvent are removed under reduced pressure to obtain HPNSi.

6. The epoxy resin adhesive for CEM-1 copper clad laminate according to claim 5, characterized in that: In step B1 of the preparation of HPNSi, the ratio of DOPO, ethanol, and ethylene glycol diglycidyl ether during the reaction is 0.2 mol: 150 mL: 0.1 mol, and the vacuum drying temperature is 80 °C. In step B2 of the preparation of HPNSi, by mass fraction, the amine component is 12-15 parts, xylene is 15-18 parts, silane component is 58-62 parts, phosphorus-containing monomer obtained in step B1 is 8-12 parts, deionized water is 0.35-0.5 parts, zinc acetate is 0.05-0.08 parts, the molar ratio of diethylenetriamine to triethylenetetramine in the amine component is 7:3, the molar ratio of γ-aminopropyltriethoxysilane to γ-aminoethylaminopropyltrimethoxysilane in the silane component is 17:3, and the dropping time of the silane component is 2.5 hours.

7. The epoxy resin adhesive for CEM-1 copper clad laminate according to claim 1, characterized in that: The curing agent is a linear phenolic resin with a softening point of 85-105℃, the accelerator is 2-methylimidazole, and the synergistic accelerator is DMP-30 or BDMA.

8. The epoxy resin adhesive for CEM-1 copper clad laminate according to claim 1, characterized in that: The leveling agent is BYK-150, the coupling agent is KH-550, the auxiliary agent is tetramethylfluorourea hexafluorophosphate, and the solvent consists of equal masses of ethanol and acetone.

9. A method for preparing an epoxy resin solution for CEM-1 copper clad laminate according to any one of claims 1 to 8, characterized in that: Includes the following steps: S1. Weigh each raw material according to the mass fraction, dissolve HBPDP in brominated epoxy resin, then add HPNSi, and stir at 80℃ for 30-40 minutes to obtain modified resin. S2. Add the solvent to the reaction vessel, heat it to 50-60℃, and then add the modified resin obtained in step S1 while stirring. Stir until it is completely dissolved to obtain a resin solution. S3. Cool the resin solution obtained in step S2 to 45-55℃, add the curing agent and continue stirring until completely dissolved to obtain the epoxy-phenolic system. S4. Cool the epoxy-phenolic system obtained in step S3 to 40-50℃, add accelerator, synergistic accelerator, leveling agent, coupling agent and auxiliary agent, and continue stirring for 30-60 minutes to obtain a mixture. Filter the mixture to remove gel particles and let it stand for 4-12 hours to obtain CEM-1 copper clad laminate epoxy resin solution.

10. The method for preparing an epoxy resin solution for CEM-1 copper clad laminate according to claim 9, characterized in that: In step S4, the mesh size of the filter is 100-200 mesh.