A diamond wire surface modification liquid and a preparation method thereof, modified diamond wire and a preparation method and application thereof

Abstract

The present application relates to the technical field of photovoltaic cutting, and particularly relates to a diamond wire surface modification liquid and a preparation method thereof, modified diamond wire and a preparation method and application thereof. The diamond wire surface modification liquid provided by the present application comprises component A and component B, the mass ratio of the component A to the component B is (40-80):(20-60); the component A comprises the following components according to mass percentage: titanium alkoxide 5%-40%, organic solvent 2%-30%, and the rest is water; the component B comprises the following components according to mass percentage: polyphenol compound 1%-10%, and the rest is water. The diamond wire surface modification liquid of the present application is used for hydrophilic modification of the diamond wire, improves the liquid carrying capacity of the diamond wire, ensures that the cutting liquid composition is effectively carried into the cutting slit in the photovoltaic cutting process, reduces the wire mark of the silicon wafer in the production process, and reduces the amount of wetting components in the cutting liquid.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic cutting technology, and in particular to a diamond wire surface modification liquid and its preparation method, modified diamond wire and its preparation method and application. Background Technology

[0002] Photovoltaic silicon wafers are a crucial component of solar panels. Silicon rods are processed into wafers using wire cutting. Traditional wire cutting uses abrasive wire, while diamond wire is now widely used in the industry. Diamond wire consists of a main wire, a nickel plating layer, and diamond abrasive. Due to the nickel plating and diamond abrasive on the outer layer, the surface of the diamond wire is hydrophobic. Therefore, without an "external force" additive during the silicon rod cutting process, the resulting silicon wafers will have very high wire marks, failing to meet usage standards. To solve this problem, an "external force" additive, cutting fluid, is introduced into the cutting process. The cutting fluid mainly consists of surfactants with lubricating, wetting, cleaning, and defoaming properties. The wetting components allow the diamond wire to carry the cutting fluid into the cutting slit, where the fluid lubricates and reduces wire marks. The cleaning components remove silicon powder generated during cutting. Because the wetting surfactants have low surface tension, they easily generate foam; therefore, defoaming surfactants are also essential.

[0003] With the rapid development of photovoltaic silicon wafers, industry competition is intensifying, driving the trend towards thinner wafers and finer lines. However, this thinning process also results in narrower slits, increasing the resistance to the cutting fluid entering the slits. This places higher demands on the fluid-carrying capacity of the diamond wire. To ensure the liquid carrying effect, it is necessary to use a wetting agent with ultra-low surface tension or increase the concentration of the wetting agent. However, the following problems exist: (1) Solubility problem: Generally speaking, the solubility of a solute in a solvent is limited. Therefore, once the concentration of the wetting agent is increased to a certain value, it cannot be increased further. In other words, the surface tension cannot be effectively reduced. (2) Foaming problem affecting cutting: Due to the ultra-low surface tension of the wetting agent, it will accelerate the generation of foam during the cutting process. However, abundant foam will affect the diamond wire from carrying the liquid into the cutting slit. (3) Cost problem: The photovoltaic industry is highly competitive. For companies to survive, cost reduction and efficiency improvement are the constant themes. Among the components of the cutting fluid, the unit cost of the wetting component is the highest. The extensive use of the wetting component in the cutting fluid will undoubtedly greatly increase the cutting cost, which is not conducive to the development of the company.

[0004] In view of this, this invention is hereby proposed. Summary of the Invention

[0005] The primary objective of this invention is to provide a diamond wire surface modification liquid that improves the hydrophilicity of the diamond wire surface and enhances the diamond wire's ability to carry liquid.

[0006] The second objective of this invention is to provide a method for preparing a diamond wire surface modification liquid, which has simple steps.

[0007] The third objective of this invention is to provide a method for preparing modified diamond wire, which improves the ability of the diamond wire to carry the effective components in the cutting fluid into the cutting slit after hydrophilic modification, and is also inexpensive.

[0008] The fourth objective of this invention is to provide a modified diamond wire with excellent liquid carrying capacity.

[0009] The fifth objective of this invention is to provide the application of modified diamond wire in photovoltaic cutting, which ensures the effective introduction of cutting fluid components, reduces the probability of wire marks during silicon rod cutting, and can reduce the addition of wetting components in the cutting fluid, thereby reducing foam generation.

[0010] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted:

[0011] In a first aspect, the present invention provides a diamond wire surface modification liquid, comprising component A and component B, wherein the mass ratio of component A to component B is (40-80):(20-60);

[0012] Component A, by mass percentage, comprises the following components: 5%–40% titanium alkoxide, 2%–30% organic solvent, and the balance being water;

[0013] Component B, by mass percentage, comprises the following components: 1% to 10% polyphenolic compounds, with the balance being water.

[0014] Furthermore, the titanium alkoxide includes at least one of tetrabutyl titanate, titanium isopropoxide, and titanium tetrachloride.

[0015] Furthermore, the organic solvent includes at least one of ethanol, propanol, and glacial acetic acid.

[0016] Furthermore, the polyphenolic compound includes at least one of dopamine, tannic acid, epicatechin gallate, and epigallocatechin gallate.

[0017] Secondly, the present invention also provides a method for preparing the diamond wire surface modification liquid as described above, comprising the following steps:

[0018] After mixing and aging components A and B, the diamond wire surface modification liquid is obtained.

[0019] Thirdly, the present invention also provides a method for preparing modified diamond wire, comprising the following steps:

[0020] The modified diamond wire is obtained by passing a diamond wire through the diamond wire surface modification liquid as described above and then gelling it.

[0021] Furthermore, the linear velocity of the diamond wire passing through the surface modification liquid is 20-30 m / min.

[0022] Furthermore, the gelation temperature is 200–250°C.

[0023] Fourthly, the present invention also provides a modified diamond wire, which is prepared by the modified diamond wire preparation method described above.

[0024] Fifthly, the present invention also provides the application of the modified diamond wire described above in photovoltaic cutting.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0026] The diamond wire surface modification liquid of this invention is used to hydrophilically modify the diamond wire, which improves the diamond wire's ability to carry liquid, ensures that the components of the cutting fluid are effectively carried into the cutting slit during photovoltaic cutting, reduces wire marks on silicon wafers during production, and improves quality. It can also reduce the amount of wetting components in the cutting fluid, appropriately reduce or eliminate them, thereby avoiding the problem of high foaming during cutting caused by the use of a large amount of low surface tension wetting agent in the cutting fluid, as well as the problem of increased production costs caused by the use of expensive wetting agents. Detailed Implementation

[0027] The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments. However, those skilled in the art will understand that the embodiments described below are some embodiments of the present invention, but not all embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0028] The following provides a detailed description of a diamond wire surface modification liquid and its preparation method, the modified diamond wire and its preparation method, and its application.

[0029] In some embodiments of the present invention, a diamond wire surface modification liquid is provided, comprising component A and component B, wherein the mass ratio of component A to component B is (40-80):(20-60);

[0030] Component A, by mass percentage, comprises the following components: 5%–40% titanium alkoxide, 2%–30% organic solvent, and the balance being water;

[0031] Component B, by mass percentage, comprises the following components: 1% to 10% polyphenolic compounds, with the balance being water.

[0032] In the diamond wire surface modification solution of the present invention, component A includes titanium alkoxide, organic solvent and water. Titanium alkoxide is the main component that hydrolyzes into a sol, the organic solvent mainly serves to dilute and store it, and water is the key to whether titanium alkoxide can be hydrolyzed. If the mass percentage of titanium alkoxide is too high, it will hinder sol formation, and if it is too low, it will be difficult to sol or not sol at all. When titanium alkoxide is dissolved in organic solvent, it will coordinate with organic solvent to form a complex. This complex can stabilize the structure of titanium alkoxide and slow down the hydrolysis reaction. Therefore, adding too much water will destroy the structure of the complex, leading to an accelerated hydrolysis reaction and making the system uncontrollable. Therefore, when preparing component A, water needs to be added slowly to allow titanium alkoxide to hydrolyze slowly and finally form a stable sol with fluidity. Component B includes polyphenolic compounds and water. When component A is directly sintered into a gel, it is difficult to obtain a uniform and dense film, and its hydrophilicity is also limited. Therefore, polyphenolic compounds are introduced to further bond with the titanium sol, enhancing the hydrophilicity and film-forming properties of the formed gel.

[0033] The diamond wire surface modification liquid of the present invention is used to modify the diamond wire to be hydrophilic, thereby improving the hydrophilicity of the diamond wire surface and the liquid carrying capacity of the diamond wire during the photovoltaic cutting process.

[0034] In some embodiments of the present invention, the mass ratio of component A to component B can be 40:60, 45:55, 50:50, 55:45, 60:40, 65:35, 70:30, 75:25, 80:20, or a range of any two of these.

[0035] In some embodiments of the present invention, the mass percentage of titanium alkoxide in component A can be 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, or any combination thereof; the mass percentage of organic solvent can be 2%, 5%, 10%, 15%, 20%, 25%, 30%, or any combination thereof.

[0036] In some embodiments of the present invention, the mass percentage of polyphenolic compounds in component B can be 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, or any combination thereof.

[0037] In some embodiments of the present invention, the diamond wire surface modification liquid includes component A and component B, wherein the mass ratio of component A to component B is (60-80):(20-40).

[0038] Component A, by mass percentage, comprises the following components: 20%–30% titanium alkoxide, 10%–20% organic solvent, and the balance being water;

[0039] Component B, by mass percentage, comprises the following components: 3% to 6% polyphenolic compounds, with the balance being water.

[0040] In some embodiments of the present invention, the titanium alkoxide includes at least one of tetrabutyl titanate, titanium isopropoxide, and titanium tetrachloride.

[0041] In some embodiments of the present invention, the organic solvent includes at least one of ethanol, propanol, and glacial acetic acid.

[0042] In some embodiments of the present invention, the polyphenolic compound includes at least one of dopamine, tannic acid, epicatechin gallate (ECG), and epigallocatechin gallate (EGCG).

[0043] In some embodiments of the present invention, a method for preparing the above-mentioned diamond wire surface modification liquid is also provided, comprising the following steps:

[0044] After mixing and aging components A and B, a diamond wire surface modification solution is obtained.

[0045] In some embodiments of the present invention, the aging time is 3 to 5 days.

[0046] In some embodiments of the present invention, the preparation method of the diamond wire surface modification liquid specifically includes the following steps:

[0047] Mix the components of component A and stir until each component is completely stable; mix the components of component B and stir until each component is completely stable; then mix components A and B and stir until each component is completely stable, and then let stand to age to form a sol, thus obtaining the diamond wire surface modification solution.

[0048] In some embodiments of the present invention, a method for preparing modified diamond wire is also provided, comprising the following steps:

[0049] The diamond wire is passed through the modified liquid on the surface of the diamond wire and gelled to obtain the modified diamond wire.

[0050] This invention involves passing a diamond wire through a surface-modifying liquid, completely immersing the diamond wire in the liquid, and then coating the diamond wire surface with the modified liquid using a dip-coating method. Following gelation, a reinforced coating is formed on the diamond wire surface. The specific principle is as follows: the complex formed by titanium alkoxide and ethanol is disrupted upon contact with water, slowly hydrolyzing into a sol primarily composed of TiO(OH)₂. Simply sintering TiO(OH)₂ into TiO₂ makes it difficult to form a uniform film. Therefore, the addition of component B allows polyphenolic substances to crosslink with TiO(OH)₂ in component A through hydrogen bonding. After drying, the polyphenolic substances exhibit good film-forming properties and enhance the hydrophilicity of the resulting film. Finally, the mixture of components A and B is carried away by the diamond wire and sintered on the wire surface to form a hydrophilic reinforced coating with good stability and hydrophilicity.

[0051] The surface of the diamond wire coated with sol-gel has improved hydrophilicity and enhanced liquid carrying capacity, ensuring the effective introduction of cutting fluid components, such as surfactants with lubricating and cleaning functions, during the cutting process, and reducing the probability of wire marks during silicon rod cutting.

[0052] After the surface of the diamond wire is modified to be hydrophilic, it has a better ability to carry the effective components in the cutting fluid into the cutting slit. Therefore, the wetting components in the cutting fluid can be appropriately reduced or eliminated, which can save production costs and increase profits.

[0053] Reducing or avoiding the use of wetting agents in the cutting fluid can reduce the problem of excessive foaming caused by the addition of low surface tension reagents.

[0054] Using the sol-gel method for modification is more cost-effective than using wetting agents to improve wetting ability.

[0055] In some embodiments of the present invention, the linear velocity of the diamond wire passing through the diamond wire surface modification liquid is 20-30 m / min.

[0056] In some embodiments of the present invention, the gelation temperature is 200–250°C.

[0057] In some embodiments of the present invention, the gelation time is 3 to 6 seconds.

[0058] In some embodiments of the present invention, the method for preparing diamond wire includes: tungsten wire mother wire is successively plated with nickel and then with diamond to obtain diamond wire.

[0059] In some embodiments of the present invention, the method for preparing modified diamond wire specifically includes the following steps:

[0060] After the tungsten wire busbar is sequentially plated with nickel, then with diamond, and then shaped in the electroplating zone, diamond wire is obtained.

[0061] The diamond wire is placed in a warm water bath (the water temperature in the warm water bath is 50-60℃) for cleaning to remove excess electroplating solution.

[0062] After being cleaned, the diamond wire enters the sol tank and passes through the diamond wire surface modification liquid at a linear speed of 20-30 m / min, so that the diamond wire surface is coated with the diamond wire surface modification liquid.

[0063] Then it enters the drying tank and undergoes gelation at 200-250°C to form a reinforced coating;

[0064] Then, the wire is sequentially washed in a warm water bath (the water temperature in the warm water bath is 50-60℃) and dried in a drying bath (the drying temperature is 70-80℃) to obtain modified diamond wire.

[0065] In some embodiments of the present invention, a modified diamond wire is also provided, which is prepared by the above-described method for preparing modified diamond wire.

[0066] The modified diamond wire of this invention has excellent surface hydrophilicity and liquid-carrying ability.

[0067] In some embodiments of the present invention, the modified diamond wire includes a diamond wire and a reinforcing coating disposed on the surface of the diamond wire; preferably, the diamond wire includes a tungsten wire mother wire and a nickel coating and a diamond layer disposed sequentially on the surface of the tungsten wire mother wire; more preferably, the thickness of the reinforcing coating is 1 to 5 μm.

[0068] In some embodiments of the present invention, the application of the above-mentioned modified diamond wire in photovoltaic cutting is also provided.

[0069] The modified diamond wire of this invention, when used in photovoltaic cutting, ensures the effective introduction of cutting fluid components, reduces the probability of wire marks during silicon rod cutting, and reduces the addition of wetting components in the cutting fluid, thereby reducing foam generation and lowering costs.

[0070] Examples 1-8

[0071] The diamond wire surface modification liquid provided in this embodiment includes component A and component B; the mass ratio of component A and component B, the components of component A and the content (wt%) of each component in component A, the components of component B and the content (wt%) of each component in component B are shown in Table 1.

[0072] Table 1

[0073]

[0074]

[0075] The preparation method of the diamond wire surface modification liquid provided in this embodiment includes the following steps:

[0076] Mix the components of component A and stir until each component is completely stable; mix the components of component B and stir until each component is completely stable; then mix components A and B and stir until each component is completely stable, and then let stand and age for 3 days to form a sol, thus obtaining the diamond wire surface modification solution.

[0077] The method for preparing modified diamond wire provided in this embodiment includes the following steps:

[0078] After the tungsten wire busbar is sequentially plated with nickel, then with diamond, and then shaped in the electroplating zone, diamond wire is obtained.

[0079] The diamond wire is placed in a warm water bath (the water temperature in the warm water bath is 50-60℃) for cleaning to remove excess electroplating solution.

[0080] After being cleaned, the diamond wire enters the sol tank and passes through the diamond wire surface modification liquid at a linear speed of 20-30 m / min, so that the diamond wire surface is coated with the diamond wire surface modification liquid.

[0081] Then it enters the drying tank and undergoes gelation at 200-250°C for 3-6 seconds to form a reinforced coating;

[0082] Then, the wire is sequentially washed in a warm water bath (the water temperature in the warm water bath is 50-60℃) and dried in a drying bath (the drying temperature is 70-80℃) to obtain modified diamond wire.

[0083] Comparative Examples 1-4

[0084] The diamond wire surface modification liquid provided in this comparative example includes component A and component B; the mass ratio of component A and component B, the components of component A and the content (wt%) of each component in component A, the components of component B and the content (wt%) of each component in component B are shown in Table 1.

[0085] Table 2

[0086]

[0087]

[0088] The preparation method of the diamond wire surface modification liquid and the preparation method of the modified diamond wire provided in this comparative example are based on Example 1.

[0089] Comparative Example 5

[0090] The diamond wire surface modification solution provided in this comparative example comprises, by mass percentage:

[0091] Ethylene glycol 200 0.5%–1%, malonic acid 0.1%–0.3%, balance water.

[0092] The preparation method of the diamond wire surface modification liquid provided in this comparative example includes:

[0093] It was prepared by dissolving ethylene glycol 200 and malonic acid in pure water at 50-60°C.

[0094] The preparation method of the modified diamond wire provided in this comparative example is based on Example 1.

[0095] Test case

[0096] The water droplet contact angle, breakage rate and wire marks of the modified diamond wires prepared in Examples 1-8 and Comparative Examples 1-5, as well as the unmodified diamond wires, were tested, and the results are shown in Table 3.

[0097] Water droplet contact angle: The test standard is GB / T 30693-2014;

[0098] Wire breakage rate, wire marks: obtained from production data.

[0099] Table 3

[0100]

[0101]

[0102] As shown in Table 3, the water droplet contact angle has no linear relationship with the breakage rate and line marks. This is because the stability of the hydrophilic coating affects the results. The unsatisfactory results of Comparative Example 5 are also due to the poor stability of the coating.

[0103] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A diamond wire surface modification liquid, characterized in that, The diamond wire surface modification liquid is obtained by mixing component A and component B, and allowing it to stand and age to form a sol; The mass ratio of component A to component B is (60~80):(20~40); Component A, by mass percentage, comprises the following components: 20%~30% titanium alkoxide, 10%~20% organic solvent, and the balance being water; Component B, by mass percentage, comprises the following components: 3% to 6% polyphenolic compounds, with the balance being water; The titanium alkoxide includes at least one of tetrabutyl titanate and titanium isopropoxide; The organic solvent includes at least one of ethanol, propanol, and glacial acetic acid; The polyphenolic compounds include at least one of dopamine, tannic acid, epicatechin gallate, and epigallocatechin gallate.

2. The method for preparing the diamond wire surface modification liquid according to claim 1, characterized in that, Includes the following steps: After mixing component A and component B and allowing them to stand and age to form a sol, the diamond wire surface modification liquid is obtained.

3. A method for preparing modified diamond wire, characterized in that, Includes the following steps: The modified diamond wire is obtained by passing a diamond wire through the diamond wire surface modification liquid described in claim 1 and gelling it.

4. The method for preparing modified diamond wire according to claim 3, characterized in that, The linear velocity of the diamond wire passing through the modified liquid on the diamond wire surface is 20~30m / min.

5. The method for preparing modified diamond wire according to claim 3, characterized in that, The gelation temperature is 200~250℃.

6. A modified diamond wire, characterized in that, It is prepared by the method described in any one of claims 3 to 5.

7. The application of the modified diamond wire as described in claim 6 in photovoltaic cutting.

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