A surface treatment agent for electronic-grade glass fiber cloth, a preparation method thereof, and an application thereof

Abstract

The application belongs to the field of glass fiber cloth treating agent, and particularly relates to a surface treating agent for electronic-grade glass fiber cloth and a preparation method and application thereof. The raw materials of the surface treating agent include, in terms of weight fractions, 2-5 parts of a coupling agent, 1-3 parts of a surfactant, 5-10 parts of a cosolvent, 0.05-0.3 parts of an acid regulator and 80-92 parts of water; the coupling agent includes a phosphoric acid ester coupling agent and an allyl-modified silane coupling agent in a mass ratio of 1:2-3. The surface treating agent has better stability and more excellent wetting and spreading performance; the glass fiber cloth treated by the surface treating agent has higher peel strength, lower water absorption, higher glass transition temperature, more excellent water resistance and heat resistance, and the preparation method is simple and suitable for industrial application.

Description

Technical Field

[0001] This invention belongs to the field of glass fiber cloth treatment agents, specifically relating to a surface treatment agent for electronic grade glass fiber cloth, its preparation method, and its application. Background Technology

[0002] Electronic-grade fiberglass cloth is made from electronic-grade fiberglass yarn through warping, sizing, weaving, desizing, and chemical treatment. It is primarily used in the manufacture of copper-clad laminates (CCLs), a fundamental material for printed circuit boards (PCBs). Electronic-grade fiberglass cloth itself cannot be used directly for PCB printing; it needs to be combined with resin to form a prepreg, which is then laminated with copper foil to create the CCL, ultimately used for PCB printing. However, pure fiberglass cloth is an inorganic fiber, while resin is an organic compound, resulting in poor compatibility and bonding. Therefore, surface treatment is usually required. Although some surface treatment agents in existing technologies can improve this, the surface treatment effect is generally poor, and the treated electronic-grade fiberglass cloth exhibits poor water resistance and heat resistance.

[0003] Chinese invention patent application CN109667149A discloses a method for producing electronic-grade glass fiber cloth for automotive electronic substrates. The specific steps are as follows: the glass fiber cloth after slurry removal undergoes silane surface treatment; the glass fiber cloth is then subjected to fiber opening, drying and shaping, surface treatment, and drying and shaping to obtain a high-performance, high-reliability finished glass fiber cloth. The treatment agent is prepared from the following raw materials in parts by weight: 974.6-987.5 parts pure water, 6-13 parts glacial acetic acid, 9-14 parts Dow Corning silane treatment agent, and 0.2-0.4 parts Kao surfactant. The treatment agent provided in this invention is an unstable solution system that changes with time and pH value, showing a tendency for dispersed phase particle size to grow, resulting in stratification and precipitation. This causes defects such as fish eyes and white spots in the electronic cloth, weakening the tensile strength of the glass fiber, and thus affecting the mechanical, electrical, and processing properties of the copper-clad laminate.

[0004] Chinese invention patent application CN103422356A discloses a surface treatment agent for electronic-grade glass fiber cloth, comprising the following components by mass percentage: 0.3%-0.9% silane coupling agent, 0.3%-0.8% acidity modifier, 0.1%-0.5% surfactant, and the remainder being deionized water. This surface treatment agent exhibits somewhat uneven wetting of the electronic-grade glass fiber cloth, which limits the effective spreading of the coupling agent on the glass fiber cloth surface.

[0005] Chinese invention patent application CN107119455A discloses a post-treatment agent for glass fiber cloth, which is composed of the following components: a vinyl-containing silane coupling agent A, an epoxy-containing silane coupling agent B, a pH adjuster, a surfactant, and deionized water; wherein the content of silane coupling agent A is 1.1-1.5 times the content of silane coupling agent B. This treatment agent still has room for improvement in terms of mechanical strength and heat resistance.

[0006] Therefore, developing a surface treatment agent with good stability, excellent wetting and spreading properties, and the ability to significantly improve the interfacial bonding between glass fiber cloth and resin is of great significance for improving the quality of copper clad laminates and expanding their application range. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention provides a surface treatment agent for electronic-grade glass fiber cloth, its preparation method, and its application.

[0008] To achieve the above-mentioned objectives of this invention, the specific technical solution adopted by this invention is as follows:

[0009] A surface treatment agent for electronic-grade glass fiber cloth, comprising, by weight, 2-5 parts of coupling agent, 1-3 parts of surfactant, 5-10 parts of co-solvent, 0.05-0.3 parts of acidity regulator, and 80-92 parts of water; wherein the coupling agent comprises phosphate ester coupling agent and allyl modified silane coupling agent in a mass ratio of 1:2-3.

[0010] Preferably, the surfactant comprises an acetylenic diol surfactant and an organosilicon surfactant in a mass ratio of 1:1-2.

[0011] More preferably, the acetylenol surfactant is SURFYNOL 104E (Evonik) or SURFYNOL 465 (Evonik); the organosilicon surfactant is SILWET L-77 (Momentive) or BYK-348 (BYK Chemicals).

[0012] Preferably, the co-solvent is ethanol and propylene glycol methyl ether in a mass ratio of 1:0.5-1.5.

[0013] Preferably, the phosphate coupling agent is selected from at least one of 6-(meth)acryloyloxyhexyl phosphate, 8-(meth)acryloyloxyoctyl phosphate, 10-(meth)acryloyloxydecyl phosphate and vinyl phosphate.

[0014] Preferably, the allyl-modified silane coupling agent is selected from at least one of allyltrimethoxysilane, allyltriethoxysilane, and 3-(N-allylamino)propyltrimethoxysilane.

[0015] Preferably, the acidity regulator is glacial acetic acid.

[0016] This invention also relates to a method for preparing the above-mentioned surface treatment agent for electronic-grade glass fiber cloth, comprising the following steps: (1) Mix the coupling agent, cosolvent and 1 / 3-1 / 2 water, stir, add acid regulator to obtain mixture A; (2) Add the surfactant to the remaining water and stir to obtain mixture B; (3) Mix mixture A and mixture B and stir to obtain the surface treatment agent.

[0017] Preferably, the stirring speed in steps (1)-(3) is 200-300 rpm and the stirring time is 10-40 min.

[0018] This invention also relates to the application of the above-mentioned surface treatment agent or the surface treatment agent prepared by the above-mentioned preparation method in electronic-grade glass fiber cloth.

[0019] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention uses a combination of phosphate ester coupling agent and allyl modified silane coupling agent. The two are anchored to the glass fiber surface through different chemical bonding mechanisms. The phosphate ester coupling agent coordinates with the metal ions on the glass fiber surface through phosphate groups, while the allyl modified silane coupling agent undergoes a condensation reaction with the silanol groups on the glass fiber surface through silanol groups, resulting in a stronger interfacial bond.

[0020] (2) This invention uses a combination of acetylenic diol surfactant and organosilicon surfactant as the surfactant system. The acetylenic diol surfactant has excellent dynamic wetting properties and can quickly reduce surface tension during high-speed coating; the organosilicon surfactant has extremely low equilibrium surface tension and can significantly improve the static wetting properties of the treatment liquid on the glass fiber surface. The two work synergistically to achieve uniform and complete coverage of the treatment liquid on the glass fiber surface. Detailed Implementation

[0021] The present invention will be further described in detail below with reference to specific embodiments. The following embodiments are not intended to limit the present invention, but only to illustrate the present invention. Unless otherwise specified, the experimental methods used in the following embodiments are generally performed under conventional conditions. Unless otherwise specified, the materials and reagents used in the following embodiments are commercially available.

[0022] Example 1 A surface treatment agent for electronic grade glass fiber cloth, by weight, comprises: 3 parts coupling agent, 2 parts surfactant, 7 parts cosolvent, 0.1 parts acidity regulator, and 88 parts deionized water.

[0023] The coupling agent is 10-(meth)acryloyloxydecyl phosphate and allyltriethoxysilane in a mass ratio of 1:2.5; the surfactant is acetylenic diol surfactant (SURFYNOL 104E) and organosilicon surfactant (SILWET L-77) in a mass ratio of 1:1.5; the cosolvent is ethanol and propylene glycol methyl ether in a mass ratio of 1:1; and the acidity regulator is glacial acetic acid.

[0024] The preparation method of the above surface treatment agent is as follows: (1) Mix the coupling agent, cosolvent and 1 / 3 water, stir at 300 rpm for 20 min, add acid regulator to obtain mixture A; (2) Add the surfactant to the remaining water and stir at 200 rpm for 15 min to obtain mixture B; (3) Mix mixture A and mixture B, stir at 250 rpm for 30 min to obtain the surface treatment agent.

[0025] Example 2 A surface treatment agent for electronic grade glass fiber cloth, by weight, comprises: 2 parts coupling agent, 1 part surfactant, 5 parts cosolvent, 0.05 parts acidity regulator, and 80 parts water.

[0026] The coupling agent is 6-(meth)acryloyloxyhexyl phosphate and allyltrimethoxysilane in a mass ratio of 1:2; the surfactant is SURFYNOL 465 and BYK-348 in a mass ratio of 1:1; the cosolvent is ethanol and propylene glycol methyl ether in a mass ratio of 1:0.5; and the acidity regulator is glacial acetic acid.

[0027] The preparation method is the same as in Example 1.

[0028] Example 3 A surface treatment agent for electronic grade glass fiber cloth, by weight, comprises: 5 parts coupling agent, 3 parts surfactant, 10 parts cosolvent, 0.2 parts acidity regulator, and 92 parts water.

[0029] The coupling agent is vinyl phosphate and 3-(N-allylamino)propyltrimethoxysilane in a mass ratio of 1:3; the surfactant is SURFYNOL 104E and BYK-348 in a mass ratio of 1:2; the cosolvent is ethanol and propylene glycol methyl ether in a mass ratio of 1:1.5; and the acidity regulator is glacial acetic acid.

[0030] The preparation method is the same as in Example 1.

[0031] Comparative Example 1 The only difference between this comparative example and Example 1 is that the coupling agent is only 10-(meth)acryloyloxydecyl phosphate.

[0032] Comparative Example 2 The only difference between this comparative example and Example 1 is that the coupling agent is allyltriethoxysilane.

[0033] Comparative Example 3 The only difference between this comparative example and Example 1 is that the coupling agent is 10-(meth)acryloyloxydecyl phosphate and allyltriethoxysilane in a mass ratio of 2.5:1.

[0034] Comparative Example 4 The only difference between this comparative example and Example 1 is that the surfactant used is only an alkynyl diol surfactant (SURFYNOL104E).

[0035] Comparative Example 5 The only difference between this comparative example and Example 1 is that the surfactant used is a silicone surfactant (SILWETL-77).

[0036] Comparative Example 6 The only difference between this comparative example and Example 1 is that the co-solvent is ethanol.

[0037] Comparative Example 7 The only difference between this comparative example and Example 1 is that the cosolvent used is propylene glycol methyl ether.

[0038] Effect test The surface treatment agents prepared in the above examples and comparative examples were used to treat electronic-grade glass fiber cloth (E-glass, 0.1 mm thick, desizing after heat treatment at 550°C). Treatment process: immersion for 5 minutes, followed by drying at 80°C to obtain pretreated glass fiber cloth.

[0039] By weight, 75 parts of epoxy resin E-44, 2.5 parts of dicyandiamide, 0.1 parts of dimethylimidazole, 28 parts of talc, and 70 parts of N,N-dimethylformamide were mixed and stirred evenly to obtain a resin solution. Pretreated electronic-grade glass fiber cloth was impregnated in the resin solution and dried at 130°C for 15 minutes to obtain a semi-cured sheet with an average thickness of 50 μm.

[0040] Four prepreg sheets were stacked together, and copper foil with a thickness of 18μm was applied to the top and bottom sides respectively. The sheets were then placed in a hot press and hot-pressed at 2MPa pressure and 200℃ for 2 hours to obtain a copper-clad laminate with a thickness of 0.2mm.

[0041] Test method: Surface tension: The surface tension (mN / m) of the treatment solution was tested using the pendant drop method. The treatment solution was drawn into a microsyringe, and a suspended droplet was formed at the drop head of the measuring instrument under constant temperature (25±1℃). Images of the droplet were captured using a high-resolution camera, and the droplet profile was fitted using the Yang-Laplace equation to calculate the surface tension value. Each sample was measured three times, and the average value was taken.

[0042] Peel strength: The copper foil peel strength (N / mm) of the copper-clad laminate was tested according to IPC-TM-650 2.4.8 method.

[0043] Water absorption rate: The water absorption rate (%) of the copper clad laminate was tested according to IPC-TM-650 2.6.2 method. Condition: immersion in water at 23℃ for 24h.

[0044] Glass transition temperature (Tg): The glass transition temperature of copper-clad laminates prepared according to the test examples of GB / T 36800.1-2018 Thermomechanical Analysis (TMA) of Plastics. The higher the glass transition temperature, the better the heat resistance.

[0045] Treatment solution stability: Let the surface treatment agent stand at 25℃ for 30 days and observe whether there is precipitation or stratification.

[0046] The test results are shown in Table 1.

[0047] Table 1 Test Results

[0048] The copper-clad laminates made from glass fiber cloth treated with the surface treatment agents of Examples 1-3 of this invention all exhibited peel strengths exceeding 1.88 N / mm, significantly higher than those of the comparative examples. This indicates a significant synergistic effect between the phosphate ester and allyl silane crosslinking agent, effectively enhancing the interfacial bonding between the glass fiber and the resin. The water absorption rate was all below 0.08%, and the Tg reached above 178°C, demonstrating that the treatment agent of this invention imparts excellent water resistance and heat resistance to the copper-clad laminates. Furthermore, the surface treatment agents of each example showed no stratification or precipitation after standing at 25°C for 30 days, indicating excellent system stability.

[0049] Comparative Examples 1 and 2 used a single coupling agent, while Comparative Example 3 used a coupling agent ratio that exceeded the scope of this invention and its performance was significantly inferior to the examples, demonstrating the necessity of multiple coupling agents and a ratio range of 1:2-3.

[0050] Comparative Example 4 used only acetylenic diol surfactant, and Comparative Example 5 used only organosilicon surfactant. Both surface treatment agents produced poor wetting and spreading properties, and the uniformity of the treatment solution's coverage on the glass fiber surface was poor, resulting in lower performance of the copper-clad laminate compared to the examples. This indicates that the specific ratio of acetylenic diol and organosilicon produces a significant synergistic effect. Acetylene diol provides rapid wetting, while organosilicon provides deep spreading. Their synergy enables the treatment solution to achieve a more uniform and complete coverage on the glass fiber surface, thereby significantly improving interfacial adhesion.

[0051] Comparative Example 6 used only ethanol as a co-solvent, which has a low boiling point and evaporates too quickly during the drying process, resulting in uneven distribution of the coupling agent. Comparative Example 7 used only propylene glycol methyl ether as a co-solvent, which had slightly poor solubility for some coupling agents, preventing them from being fully hydrolyzed and dispersed. Both of these resulted in poor surface treatment and decreased copper-clad laminate performance. However, the combination of ethanol and propylene glycol methyl ether ensured the full dissolution and hydrolysis of the coupling agent, while propylene glycol methyl ether slowed down the evaporation process, promoting uniform distribution of the coupling agent on the glass fiber surface, thus achieving a better treatment effect.

[0052] The above detailed description is a specific description of one of the feasible embodiments of the present invention. This embodiment is not intended to limit the patent scope of the present invention. All equivalent implementations or modifications that do not depart from the present invention should be included within the scope of the technical solution of the present invention.

Claims

1. A surface treatment agent for electronic-grade glass fiber cloth, characterized in that, The raw materials of the surface treatment agent, by weight, include: 2-5 parts coupling agent, 1-3 parts surfactant, 5-10 parts cosolvent, 0.05-0.3 parts acidity regulator and 80-92 parts water; the coupling agent includes phosphate ester coupling agents and allyl modified silane coupling agents in a mass ratio of 1:2-3.

2. The surface treatment agent for electronic-grade glass fiber cloth according to claim 1, characterized in that, The surfactant comprises an acetylenic diol surfactant and an organosilicon surfactant in a mass ratio of 1:1-2.

3. The surface treatment agent for electronic-grade glass fiber cloth according to claim 2, characterized in that, The acetylenol surfactant is SURFYNOL 104E or SURFYNOL 465; the organosilicon surfactant is SILWET L-77 or BYK-348.

4. The surface treatment agent for electronic-grade glass fiber cloth according to claim 1, characterized in that, The co-solvent is ethanol and propylene glycol methyl ether in a mass ratio of 1:0.5-1.

5.

5. The surface treatment agent for electronic-grade glass fiber cloth according to claim 1, characterized in that, The phosphate ester coupling agent is selected from at least one of 6-(meth)acryloyloxyhexyl phosphate, 8-(meth)acryloyloxyoctyl phosphate, 10-(meth)acryloyloxydecyl phosphate and vinyl phosphate.

6. The surface treatment agent for electronic-grade glass fiber cloth according to claim 1, characterized in that, The allyl-modified silane coupling agent is selected from at least one of allyltrimethoxysilane, allyltriethoxysilane, and 3-(N-allylamino)propyltrimethoxysilane.

7. The surface treatment agent for electronic-grade glass fiber cloth according to claim 1, characterized in that, The acid regulator is glacial acetic acid.

8. A method for preparing a surface treatment agent for electronic-grade glass fiber cloth according to any one of claims 1-7, characterized in that, Includes the following steps: (1) Mix the coupling agent, cosolvent and 1 / 3-1 / 2 water, stir, add acid regulator to obtain mixture A; (2) Add the surfactant to the remaining water and stir to obtain mixture B; (3) Mix mixture A and mixture B and stir to obtain the surface treatment agent.

9. The preparation method according to claim 8, characterized in that, The stirring speed in steps (1)-(3) is 200-300 rpm and the stirring time is 10-40 min.

10. The application of a surface treatment agent according to any one of claims 1-7 or a surface treatment agent prepared by the preparation method according to any one of claims 8-9 in electronic-grade glass fiber cloth.

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