Composite coupling agent and application thereof in enhancing peel strength of copper foil

Abstract

The invention relates to a composite coupling agent and application thereof in enhancing the peel strength of a copper foil. The coupling agent is a compound capable of enhancing the interaction between the high polymer material and the inorganic filler so as to achieve the functions of enhancing interface adhesion, improving or enhancing the performance of the composite material and the like, and when the coupling agent is used in the production of the copper foil, a layer of protective film can be formed on the surface of the copper foil to increase the oxidation resistance, and the anti-stripping strength of the copper foil can also be improved. According to the composite coupling agent provided by the invention, the phosphate coupling agent and the borate coupling agent are mixed in the silane coupling agent to generate a synergistic effect with the silane coupling agent, so that the anti-stripping strength of the copper foil is remarkably enhanced.

Description

Technical Field

[0001] The invention relates to the technical field of electrolytic copper foil production, in particular to a composite coupling agent and application thereof in enhancing the anti-peeling strength of copper foil. Background Art

[0002] The composite interface of copper foil and resin requires a low dielectric constant resin, and the roughness of the copper foil surface must be reduced to reduce the transmission loss of high-frequency signals. However, this will weaken the bonding strength of the copper foil / resin interface, which will make the interface failure of the board more likely to occur under high temperature and high humidity environments. Therefore, in the industrial production process, the copper foil surface is usually modified with a silane coupling agent to enhance the bonding strength between the copper foil and the resin.

[0003] Coupling agent is a compound that can enhance the interaction between polymer materials and inorganic fillers, thereby enhancing interfacial adhesion, improving or enhancing the performance of composite materials, and other functions. During the surface treatment of electrolytic copper foil, silane coupling agent is coated on the surface of copper foil to increase the oxidation resistance and peel strength of copper foil. However, a single silane coupling agent has a problem of little increase in peel strength, resulting in unqualified peel strength of the produced product. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a composite coupling agent for enhancing the peeling strength of copper foil. A phosphate coupling agent and a boric acid coupling agent are mixed in a silane coupling agent to produce a synergistic effect with the silane coupling agent, thereby significantly enhancing the peeling strength of copper foil.

[0005] The technical solution provided by the present invention is:

[0006] The first object of the present invention is to provide a composite coupling agent, wherein the composite silane coupling agent comprises a silane coupling agent, a phosphate coupling agent and a borate coupling agent.

[0007] In one embodiment of the present invention, the general formula of the silane coupling agent is silane coupling agent KBM403.

[0008] In one embodiment of the present invention, the phosphate coupling agent is ethylene glycol methyl phosphate coupling agent.

[0009] In one embodiment of the present invention, the borate coupling agent is a methacryloyl borosilane coupling agent.

[0010] In one embodiment of the present invention, the addition ratio of the silane coupling agent, the phosphate coupling agent and the borate coupling agent is 6:2:2.

[0011] In one embodiment of the present invention, the mass concentration of the silane coupling agent is 0.8-3%; the mass concentration of the phosphate coupling agent is 0.5-2%; the mass concentration of the borate coupling agent is 0.5-2%; and the solvent is water.

[0012] The second object of the present invention is to provide the use of the composite coupling agent in preparing a copper foil with enhanced peeling strength.

[0013] In one embodiment of the present invention, the method of application is:

[0014] The surface of the pretreated copper foil is coated with a composite coupling agent and dried.

[0015] In one embodiment of the present invention, the drying temperature is 120°C to 250°C.

[0016] The third object of the present invention is to provide a copper foil with enhanced anti-stripping performance, which is obtained by coating a composite coupling agent on the surface of the copper foil.

[0017] In one embodiment of the present invention, the composite coupling agent includes a silane coupling agent, a phosphate coupling agent and a borate coupling agent.

[0018] In the present invention, the molecular formula of the silane coupling agent is CH(O)CH-(CH2)3-Si-(CH3O)3. During the spraying process, -Si-(CH3O)3 is hydrolyzed to generate silanol (Si(OH)3), which combines with inorganic substances to generate siloxane; CH(O)CH can react with organic substances to combine. Therefore, the silane coupling agent can build a "molecular bridge" between the interface of inorganic and organic substances, connecting two materials with very different properties together to improve the performance of the composite material and increase the bonding strength, thereby enhancing the bonding force between the copper foil and the resin and enhancing the peeling resistance.

[0019] It can be expressed as:

[0020]

[0021] The general formula of phosphate coupling agent is RO-Ti-(OC 14 H 15 O2P-OH)2, where R is ethylene glycol methyl; the phosphate coupling agent can react with free protons (H+) at the copper foil interface to form an organic monolayer. Since the interface does not form a multi-molecular layer and the special chemical structure of the phosphate coupling agent, the resulting lower surface energy greatly reduces the viscosity. The copper foil treated with the phosphate coupling agent is organic-friendly, and the phosphate coupling agent can be used together with the silane coupling agent to produce a synergistic effect. It can be expressed as:

[0022]

[0023] The general formula of borate coupling agent is B(OR)3, where R is methacryloyl; borate coupling agent has antistatic properties, flame retardancy and excellent surface activity, which can be expressed as:

[0024]

[0025] The above technical solution of the present invention has the following advantages compared with the prior art:

[0026] (1) The present invention provides a composite coupling agent for enhancing the peel strength of copper foil. Ordinary silane coupling agents can enhance the peel strength of copper foil by 0.3 KN / m to 0.4 KN / m, while the composite coupling agent of the present invention can enhance the peel strength by 0.6 KN / m to 0.8 KN / m after being sprayed on the surface of copper foil.

[0027] (2) The composite coupling agents have a synergistic effect. Silane can combine with both organic and inorganic substances to increase the peel strength. Phosphate coupling agents can react with free protons (H+) at the copper foil interface to form an organic monolayer, which increases the peel strength of silane. Borate coupling agents can enhance the surface activity and antistatic properties of copper foil, allowing copper foil to be used on different substrates. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific embodiments of the present invention in conjunction with the accompanying drawings, wherein

[0029] Figure 1 It is a flow chart of the anti-stripping detection method in the present invention. DETAILED DESCRIPTION

[0030] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0031] The anti-peeling detection method involved in the present invention (specific flow chart as shown in Figure 1 As shown) as follows:

[0032] 1. Cut a 160mm×40mm sample from the pressed copper-clad laminate on a shearing machine, and use a sharp utility knife to mark 9 lines at a scale of 3±0.15mm;

[0033] 2. Pull off each line manually from left to right, and peel off one end of the remaining three lines with a blade to a length of 15mm-20mm;

[0034] 3. Clamp the sample strip on the lower fixture of the peeling strength tester, with the circuit side facing upwards and the single circuit completely in the middle of the fixture slot. Clamp the stripped section of the circuit vertically on the upper fixture of the peeling strength tester;

[0035] 4. Click Force Return to Zero and Displacement Return to Zero to start the test. After the test is completed, the device will automatically return to its original position and record the values.

[0036] 5. After the test is completed, the computer will automatically generate data. Pull three pieces of data and use a steel ruler to measure whether the width is 3mm. If not, manually rewrite the actual value in the computer width position and take a similar value and write it on the board.

[0037] 6. After getting the value, soak it in 1:1 hydrochloric acid for 30 minutes, take it out, rinse it with water, and pull it on the peel strength tester (two or more lines need to be pulled). The pulled value and the value before soaking in hydrochloric acid cannot exceed 0.04mm;

[0038] 7. Take the degradation rate, degradation rate = (anti-stripping value before soaking in hydrochloric acid - anti-stripping value after soaking in hydrochloric acid) / anti-stripping value before soaking in hydrochloric acid × 100%.

[0039] Example 1

[0040] This embodiment provides a method for coating a composite coupling agent on a surface of a copper foil, comprising the following steps:

[0041] (1) The raw foil produced in the electrolysis process is subjected to surface treatment such as pickling, roughening, curing, roughening, curing, roughening, curing, galvanizing, nickel plating, chrome plating, etc. on a surface treatment machine;

[0042] (2) A silane coupling agent, a phosphate coupling agent and a borate coupling agent are mixed in a ratio of 6:2:2 to obtain a composite coupling agent; wherein the silane coupling agent is silane coupling agent KBM403, with a mass concentration of 1.5%; the phosphate coupling agent is ethylene glycol methyl phosphate coupling agent, with a mass concentration of 0.5%; the borate coupling agent is methacryloyl boric acid silane coupling agent, with a mass concentration of 0.5%; and the solvent is water.

[0043] Then, the composite coupling agent is sprayed on the surface of the copper foil after surface treatment in a surface treatment machine, and then dried (120° C.-250° C.).

[0044] (3) The peel strength of the rough surface of the copper foil was tested and the result was 0.39KN / m.

[0045] Comparative Example 1

[0046] This comparative example provides a method for coating a silane coupling agent on the surface of a copper foil, comprising the following steps:

[0047] (1) The raw foil produced in the electrolysis process is subjected to surface treatment such as pickling, roughening, curing, roughening, curing, roughening, curing, galvanizing, nickel plating, chrome plating, etc. on a surface treatment machine;

[0048] (2) spraying the surface of the copper foil after surface treatment with a silane coupling agent KBM403 (concentration of 1.5%) on a surface treatment machine, and then drying;

[0049] (3) Test the peel strength of the rough surface of copper foil, and the strength is increased by 0.21KN / m.

[0050] Comparative Example 2

[0051] This comparative example provides a method for coating a silane coupling agent on the surface of a copper foil, comprising the following steps:

[0052] (1) The raw foil produced in the electrolysis process is subjected to surface treatment such as pickling, roughening, curing, roughening, curing, roughening, curing, galvanizing, nickel plating, chrome plating, etc. on a surface treatment machine;

[0053] (2) spraying a phosphate coupling agent (ethylene glycol methyl phosphate coupling agent, concentration of 0.5%) on the surface of the copper foil after surface treatment in a surface treatment machine, and then drying;

[0054] (3) Test the peel strength of the rough surface of copper foil, and the strength is enhanced by 0.12KN / m.

[0055] Comparative Example 3

[0056] This comparative example provides a method for coating a silane coupling agent on the surface of a copper foil, comprising the following steps:

[0057] (1) The raw foil produced in the electrolysis process is subjected to surface treatment such as pickling, roughening, curing, roughening, curing, roughening, curing, galvanizing, nickel plating, chrome plating, etc. on a surface treatment machine;

[0058] (2) spraying a phosphate coupling agent (methacryloyl boric acid silane coupling agent, concentration of 0.5%) on the surface of the copper foil after surface treatment in a surface treatment machine, and then drying;

[0059] (3) Test the peel strength of the rough surface of copper foil, and the strength is increased by 0.14KN / m.

[0060] Example 2

[0061] The copper foil prepared by using the composite coupling agent in Example 1 was used on different substrates. The current mainstream substrate types are: composite substrate, glass fiber cloth substrate, metal, ceramic substrate, paper substrate. The degree of peeling resistance increase of different substrates was tested, and the results are shown in Table 1:

[0062] Table 1 Anti-peeling increase results of different substrates

[0063]

[0064] As can be seen from Table 1, through the synergistic effect between the composite coupling agents, silane can be combined with both organic and inorganic substances to increase the peel strength. Phosphate coupling agents can react with free protons (H+) at the copper foil interface to form an organic monolayer, which increases the peel strength of silane. Borate coupling agents can enhance the surface activity and antistatic properties of copper foil, allowing copper foil to be used on different substrates to expand its application range.

[0065] Obviously, the above embodiments are merely examples for clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the protection scope of the invention.

Claims

1. A composite coupling agent, characterized in that: The composite silane coupling agent comprises a silane coupling agent, a phosphate coupling agent and a borate coupling agent.

2. The composite coupling agent according to claim 1, characterized in that: The general formula of the silane coupling agent is silane coupling agent KBM403.

3. The composite coupling agent according to claim 1, characterized in that: The phosphate coupling agent is ethylene glycol methyl phosphate coupling agent.

4. The composite coupling agent according to claim 1, characterized in that: The borate coupling agent is a methacryloyl boric acid silane coupling agent.

5. The composite coupling agent according to claim 1, characterized in that: The mass ratio of the silane coupling agent, the phosphate coupling agent and the borate coupling agent is 3:(0.5-2):(0.5-2).

6. Use of the composite coupling agent according to any one of claims 1 to 5 in preparing a copper foil with enhanced peel strength.

7. The use according to claim 6, characterized in that: The method of application is: The surface of the pretreated copper foil is coated with a composite coupling agent and dried.

8. The use according to claim 7, characterized in that: The drying temperature is 120°C to 250°C.

9. A copper foil with enhanced anti-stripping performance, characterized in that: It is obtained by coating a composite coupling agent on the surface of copper foil.

10. The copper foil according to claim 9, characterized in that The composite coupling agent comprises a silane coupling agent, a phosphate coupling agent and a borate coupling agent.

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