Diamond wire surface modification liquid, preparation method of diamond wire surface modification liquid, modified diamond wire and preparation method and application of modified diamond wire

Abstract

The invention relates to the technical field of photovoltaic cutting, in particular to diamond wire surface modification liquid, a preparation method of the diamond wire surface modification liquid, a modified diamond wire and a preparation method and application of the modified diamond wire. The diamond wire surface modification liquid provided by the invention comprises a component A and a component B, and the mass ratio of the component A to the component B is (40-80): (20-60); the component A is prepared from the following components in percentage by mass: 5 to 40 percent of titanium alkoxide, 2 to 30 percent of organic solvent and the balance of water; the component B is prepared from the following components in percentage by mass: 1 to 10 percent of polyphenol compounds and the balance of water. Hydrophilic modification is carried out on the diamond wire by adopting the diamond wire surface modification liquid, the liquid carrying capacity of the diamond wire is improved, it is guaranteed that components of the cutting liquid are effectively carried into cutting slits in the photovoltaic cutting process, and wire marks of silicon wafers in the production process are reduced; and the use amount of wetting components in the cutting fluid is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of photovoltaic cutting, and in particular to a diamond wire surface modification liquid and a preparation method thereof, a modified diamond wire and a preparation method and application thereof. Background Art

[0002] Photovoltaic silicon wafers are an important part of solar panels. Silicon rods can be processed into silicon wafers by wire cutting. Traditional wire cutting uses sand wire, and diamond wire is widely used in the current industry. Diamond wire is composed of mother wire, nickel plating and diamond sand. Since the outer layer is nickel plating and diamond sand, the surface of diamond wire is hydrophobic. Therefore, in the process of cutting silicon rods, if there is no "external force" auxiliary agent, the line marks of the produced silicon wafers will be very high and do not meet the use standards. In order to solve this problem, "external force" auxiliary agent cutting fluid is introduced into the cutting. The cutting fluid is mainly composed of surfactant components with lubricating, wetting, cleaning, defoaming and other functions. The wetting component can make the diamond wire bring the cutting fluid into the cutting slit, and then the cutting fluid plays a role of lubrication and reducing line marks in the cutting slit. The cleaning component can take away the silicon powder produced by cutting. Since the surfactant components with wetting effect are all low surface tension, it is easy to generate foam, so the surfactant with defoaming effect is also indispensable.

[0003] With the rapid development of photovoltaic silicon wafers, the industry competition is intensifying, which makes photovoltaic silicon wafers develop in the direction of thinner and finer lines. However, the thinning of thin wafers also makes the cutting slit width narrower and the resistance of cutting fluid entering the cutting slit is also increasing, which puts higher requirements on the liquid carrying capacity of diamond wire. In order 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, but there are the following problems: (1) Solubility problem: Generally speaking, the solubility of a solute in a solvent is limited. Therefore, when the concentration of the wetting agent reaches a certain value, it cannot be increased any further. In other words, the surface tension cannot be effectively reduced. (2) Foam affects cutting: Since the wetting agent has ultra-low surface tension characteristics, the wetting agent will increase the speed of foam generation during the cutting process. However, abundant foam will affect the diamond wire from bringing 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 unchanging themes. Among the cutting fluid components, the unit price of the wetting component is the highest. The large-scale use of wetting components 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 proposed. Summary of the invention

[0005] The first object of the present invention is to provide a diamond wire surface modification liquid, which improves the hydrophilicity of the diamond wire surface and enhances the liquid-carrying capacity of the diamond wire.

[0006] The second object of the present invention is to provide a method for preparing a diamond wire surface modification liquid with simple steps.

[0007] The third object of the present invention is to provide a method for preparing a modified diamond wire. After the surface of the diamond wire is hydrophilically modified, the ability of the diamond wire to bring effective components in the cutting fluid into the cutting slit is improved, and the cost is low.

[0008] A fourth object of the present invention is to provide a modified diamond wire having excellent liquid carrying capacity.

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

[0010] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are particularly 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] The component A comprises the following components by mass percentage: 5% to 40% titanium alkoxide, 2% to 30% organic solvent, and the balance water;

[0013] The component B comprises the following components by mass percentage: 1% to 10% of polyphenol compounds and the remainder is 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 polyphenol compound includes at least one of dopamine, tannic acid, epicatechin gallate and epigallocatechin gallate.

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

[0018] The diamond wire surface modification liquid is obtained by mixing component A and component B and aging them.

[0019] In a third aspect, the present invention further provides a method for preparing a modified diamond wire, comprising the following steps:

[0020] The modified diamond wire is obtained by passing the diamond wire surface modification liquid as described above through gelation.

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

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

[0023] In a fourth aspect, the present invention further provides a modified diamond wire, which is prepared by the preparation method of the modified diamond wire as described above.

[0024] In a fifth aspect, the present invention also provides the use of the modified diamond wire as described above in photovoltaic cutting.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The diamond wire surface modification liquid of the present invention is used to perform hydrophilic modification on the diamond wire, thereby improving the liquid carrying capacity of the diamond wire, ensuring that the cutting liquid components are effectively brought into the cutting slit during photovoltaic cutting, reducing the line marks of silicon wafers during the production process, and improving the quality; the amount of wetting components in the cutting liquid can be reduced, appropriately reduced or not added, thereby avoiding the problem of high foaming during the cutting process caused by the large amount of low surface tension wetting agents used in the cutting liquid and the problem of increased production costs caused by the use of expensive wetting agents. DETAILED DESCRIPTION

[0027] The technical scheme of the present invention will be clearly and completely described below in conjunction with specific embodiments, but it will be appreciated by those skilled in the art that the following described embodiments are part of embodiments of the present invention, rather than all embodiments, and are only used to illustrate the present invention, and should not be considered as limiting the scope of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work, all belong to the scope of protection of the present invention. If specific conditions are not indicated in the embodiments, they are carried out according to normal conditions or conditions recommended by the manufacturer. If the manufacturer is not indicated in the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0028] The following specifically describes a diamond wire surface modification liquid and a preparation method thereof, a modified diamond wire and a preparation method and application thereof of the present invention.

[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, in terms of mass percentage, comprises the following components: 5% to 40% titanium alkoxide, 2% to 30% organic solvent, and the balance water;

[0031] Component B, by mass percentage, comprises the following components: 1% to 10% of polyphenol compounds, and the balance is water.

[0032] In the surface modification liquid of the diamond wire of the present invention, component A comprises titanium alkoxide, organic solvent and water, titanium alkoxide is the main body of hydrolysis into sol, organic solvent mainly plays the role of dilution and storage, and water is the key to whether titanium alkoxide can be hydrolyzed; too high a mass percentage of titanium alkoxide will hinder solization, and too low a mass percentage will make it difficult to sol or not solize; when titanium alkoxide is dissolved in an organic solvent, it will coordinate with the organic solvent to form a complex, and the complex can stabilize the structure of titanium alkoxide and slow down the occurrence of hydrolysis reaction. Therefore, adding too much water will destroy the structure of the complex, resulting in accelerated hydrolysis reaction and making the system uncontrollable. Therefore, when preparing component A, it is necessary to slowly drip water to allow titanium alkoxide to slowly hydrolyze and finally form a stable sol with fluidity; component B comprises polyphenol compounds and water. When component A is directly sintered into a gel, it is difficult to obtain a uniform and dense film, and the hydrophilicity is also limited. Therefore, the polyphenol compounds are introduced to further adhere to the titanium sol, thereby enhancing the hydrophilicity and film-forming property of the formed gel.

[0033] The diamond wire surface modification liquid of the present invention is used to perform hydrophilic modification on the diamond wire, thereby improving the hydrophilicity of the surface of the diamond wire 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 may be 40:60, 45:55, 50:50, 55:45, 60:40, 65:35, 70:30, 75:25, 80:20 or a range consisting of any two of them.

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

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

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

[0038] Component A, in terms of mass percentage, comprises the following components: 20% to 30% titanium alkoxide, 10% to 20% organic solvent, and the balance water;

[0039] Component B, by mass percentage, comprises the following components: 3% to 6% of polyphenol compounds, and the balance is 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 diamond wire surface modification liquid is also provided, comprising the following steps:

[0044] The diamond wire surface modification liquid is obtained by mixing component A and component B and aging them.

[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 method for preparing the diamond wire surface modification liquid specifically comprises the following steps:

[0047] The components of component A are mixed and stirred until the components are completely stable; the components of component B are mixed and stirred until the components are completely stable; then component A and component B are mixed and stirred until the components are completely stable, and then allowed to stand and age to form a sol to obtain a diamond wire surface modification liquid.

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

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

[0050] The present invention allows the diamond wire to pass through a diamond wire surface modification liquid, the diamond wire is completely immersed in the diamond wire surface modification liquid, the diamond wire surface modification liquid is applied to the surface of the diamond wire by a dip coating method, and then gelation is performed to form a reinforcement coating on the surface of the diamond wire. The specific principle is as follows: the complex formed by titanium alkoxide and ethanol is destroyed after encountering water, and slowly hydrolyzes into a sol whose main component is TiO(OH)2; if TiO(OH)2 is simply sintered into TiO2, it is difficult to form a uniform film, therefore, after adding component B, polyphenols will be cross-linked with TiO(OH)2 in component A through the action of hydrogen bonds, and polyphenols will have better film-forming properties after drying, and can enhance the hydrophilicity of the resulting film; finally, the mixture of component A and component B is carried away by the diamond wire, and sintered on the surface of the steel wire into a hydrophilic reinforcement coating with good stability and hydrophilicity.

[0051] After sol-gel coating, the hydrophilicity of the diamond wire surface is improved, and the liquid carrying capacity is enhanced, which ensures the effective introduction of cutting liquid components, such as surfactants with lubricating and cleaning functions, during the cutting process, and reduces the probability of wire marks during silicon rod cutting.

[0052] After the surface of the diamond wire is hydrophilically modified, it has a better ability to bring the effective ingredients in the cutting fluid into the cutting slit. Therefore, the wetting components in the cutting fluid can be appropriately reduced or not added, which can save production expenses and increase profits.

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

[0054] The modification by sol-gel method is cheaper than using wetting agents to improve the wetting ability.

[0055] In some embodiments of the present invention, the linear speed of the diamond wire passing through the diamond wire surface modification liquid is 20 to 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, a method for preparing a diamond wire comprises: a tungsten wire mother bar is subjected to nickel plating and diamond plating in sequence to obtain a diamond wire.

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

[0060] The tungsten wire busbar is successively nickel plated, diamond plated and formed in the electroplating area to obtain a diamond wire;

[0061] The diamond wire enters the warm water tank (the water temperature in the warm water tank is 50-60°C) for cleaning, and the excess electroplating solution is cleaned;

[0062] The cleaned diamond wire enters the sol tank and passes through the diamond wire surface modification liquid at a line speed of 20 to 30 m / min, so that the surface of the diamond wire is coated with the diamond wire surface modification liquid;

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

[0064] Then, the wire is sequentially placed in a warm water tank (the water temperature in the warm water tank is 50-60° C.) for washing and in a drying tank for drying (the drying temperature is 70-80° C.) to obtain a modified diamond wire.

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

[0066] The modified diamond wire of the invention has excellent surface hydrophilicity and liquid carrying capacity.

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

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

[0069] The modified diamond wire of the present invention is used in photovoltaic cutting to ensure effective introduction of cutting liquid components, reduce the probability of wire marks during silicon rod cutting, and can reduce the addition of wetting components in the cutting liquid, thereby reducing the generation of foam and reducing costs.

[0070] Examples 1 to 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 combination A and the content (wt%) of each component in component A, the components of combination B and the content (wt%) of each component in component B are shown in Table 1.

[0072] Table 1

[0073]

[0074]

[0075] The method for preparing the diamond wire surface modification liquid provided in this embodiment comprises the following steps:

[0076] The components of component A are mixed and stirred until the components are completely stable; the components of component B are mixed and stirred until the components are completely stable; then component A and component B are mixed and stirred until the components are completely stable, and then allowed to stand and age for 3 days to form a sol to obtain a diamond wire surface modification liquid.

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

[0078] The tungsten wire busbar is successively nickel plated, diamond plated and formed in the electroplating area to obtain a diamond wire;

[0079] The diamond wire enters the warm water tank (the water temperature in the warm water tank is 50-60°C) for cleaning, and the excess electroplating solution is cleaned;

[0080] The cleaned diamond wire enters the sol tank and passes through the diamond wire surface modification liquid at a line speed of 20 to 30 m / min, so that the surface of the diamond wire is coated with the diamond wire surface modification liquid;

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

[0082] Then, the wire is sequentially placed in a warm water tank (the water temperature in the warm water tank is 50-60° C.) for washing and in a drying tank for drying (the drying temperature is 70-80° C.) to obtain a modified diamond wire.

[0083] Comparative Examples 1 to 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 combination A and the content (wt%) of each component in component A, and the components of combination 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 refer to Example 1.

[0089] Comparative Example 5

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

[0091] Ethylene glycol 200 0.5%~1%, malonic acid 0.1%~0.3%, and the balance is water.

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

[0093] Ethylene glycol 200 and malonic acid are dissolved in pure water at 50-60°C to prepare the mixture.

[0094] The preparation method of the modified diamond wire provided in this comparative example refers to Example 1.

[0095] Test example

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

[0097] Water drop contact angle: the test standard is GBT 30693-2014;

[0098] Wire breakage rate and line marks: obtained from production data.

[0099] Table 3

[0100]

[0101]

[0102] As can be seen from Table 3, the water drop contact angle is not in a linear relationship with the line breakage rate and line mark, which is due to the stability of the hydrophilic coating; the unsatisfactory effect of comparative example 5 is 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, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements 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 invention comprises component A and component B, wherein the mass ratio of component A to component B is (40-80): (20-60); The component A comprises the following components by mass percentage: 5% to 40% titanium alkoxide, 2% to 30% organic solvent, and the balance water; The component B comprises the following components by mass percentage: 1% to 10% of polyphenol compounds and the remainder is water.

2. The diamond wire surface modification liquid according to claim 1, characterized in that: The titanium alkoxide includes at least one of tetrabutyl titanate, titanium isopropoxide and titanium tetrachloride.

3. The diamond wire surface modification liquid according to claim 1, characterized in that: The organic solvent includes at least one of ethanol, propanol and glacial acetic acid.

4. The diamond wire surface modification liquid according to claim 1, characterized in that: The polyphenol compound includes at least one of dopamine, tannic acid, epicatechin gallate and epigallocatechin gallate.

5. The method for preparing a diamond wire surface modification liquid according to any one of claims 1 to 4, characterized in that: The steps include: The diamond wire surface modification liquid is obtained by mixing component A and component B and aging them.

6. A method for preparing a modified diamond wire, characterized in that: The steps include: The modified diamond wire is obtained by passing a diamond wire through the diamond wire surface modification liquid according to any one of claims 1 to 4 and gelling the diamond wire.

7. The method for preparing the modified diamond wire according to claim 6, characterized in that: The linear speed of the diamond wire passing through the diamond wire surface modification liquid is 20 to 30 m / min.

8. The method for preparing the modified diamond wire according to claim 6, characterized in that: The gelation temperature is 200-250°C.

9. A modified diamond wire, characterized in that: The modified diamond wire is prepared by the preparation method of any one of claims 6 to 8.

10. Use of the modified diamond wire according to claim 9 in photovoltaic cutting.

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