Novel epoxy adhesive as well as preparation method and application thereof

Abstract

The invention provides a novel epoxy adhesive as well as a preparation method and application thereof. In the preparation of the epoxy adhesive, the carbon dioxide-based polyol is adopted to replace the traditional polyol to prepare the adhesive, so that the use of fossil resources can be reduced, the carbon footprint is reduced, the environment is protected, the green development is realized, and the epoxy resin prepared from the carbon dioxide-based polyol has higher bonding strength and hardness.

Description

Technical Field

[0001] The invention relates to the field of photovoltaic technology, in particular to a novel epoxy adhesive and a preparation method and application thereof. Background Art

[0002] At the photovoltaic slicing end, epoxy adhesive is an important auxiliary material in the silicon wafer cutting process, and epoxy resin is one of the important raw materials for epoxy adhesive. Traditional epoxy resin is prepared by ring-opening polymerization of propylene oxide and polyols in petrochemical resources. Petrochemical resources are non-renewable resources and are becoming increasingly depleted. Large-scale use of petrochemical resources will also cause damage to the environment.

[0003] Carbon dioxide-based polyols are formed by the polymerization of carbon dioxide and propylene oxide. They are a random block copolymer of polycarbonate and polyether. The epoxy resin generated by the reaction with epichlorohydrin can replace the traditional epoxy resin in epoxy adhesives and improve the bonding strength and hardness of epoxy adhesives. Summary of the invention

[0004] The object of the present invention is to provide a novel epoxy adhesive and a preparation method thereof. The method adopts carbon dioxide-based polyols to replace the polyols used in the synthesis of traditional epoxy resins. Based on the structure and source of the carbon dioxide-based polyols, the obtained novel epoxy adhesive can not only obtain better performance, such as improved bonding strength and hardness, but also reduce the use of fossil resources, reduce carbon footprint and carbon emissions, protect the environment, and promote green development.

[0005] To achieve the above object, the present invention provides the following technical solutions: In a first aspect, the present invention provides a method for preparing a carbon dioxide-based epoxy resin, comprising adding a carbon dioxide-based polyol and epichlorohydrin in a reaction system in proportion, reacting in a solvent in the presence of a base, and separating to obtain the carbon dioxide-based epoxy resin.

[0006] Preferably, the carbon dioxide-based polyol used has a carbon dioxide content of 10-40 wt %, a carbonate unit content of 30-70 wt %, a hydroxyl value of 37-56 mg KOH / g, and a viscosity of 6000-11000 mPas / 70° C.

[0007] Furthermore, in the reaction system, the molar ratio of the carbon dioxide-based polyol to epichlorohydrin is between 1:6 and 1:10, and 30 to 50 wt% of sodium hydroxide or potassium hydroxide is added as a catalyst, the amount of the alkali is 1 to 3 times the hydroxyl value, and excess epichlorohydrin acts as a solvent. The reaction process is first stirred at 20 to 40° C. for 2 to 5 hours and then heated to reflux for 3 hours.

[0008] In a second aspect, the present invention provides an epoxy adhesive, comprising component A and component B, wherein component A comprises 40 to 50 parts of epoxy resin, 5 to 10 parts of degumming factor, 30 to 50 parts of filler, 0.1 to 0.5 parts of defoaming agent, and 0 to 0.5 parts of anti-settling agent in parts by weight; component B comprises 10 to 15 parts of polythiol, 25 to 30 parts of modified amine, 0.5 to 3 parts of accelerator, 5 to 10 parts of diluent, 0.1 to 0.5 parts of defoaming agent, and 0 to 0.5 parts of anti-settling agent in parts by weight, wherein the epoxy resin is a carbon dioxide-based epoxy resin prepared by the method as described above.

[0009] Preferably, component A comprises 45 parts of epoxy resin, 5 parts of degumming factor, 35 parts of filler, 0.1 parts of defoamer, and 0.5 parts of anti-settling agent by weight; component B comprises 15 parts of polythiol, 30 parts of modified amine, 2 parts of accelerator, 5 parts of diluent, 0.1 parts of defoamer, and 0.5 parts of anti-settling agent by weight, wherein the epoxy resin is a carbon dioxide-based epoxy resin prepared by the method as described above.

[0010] Preferably, in the component A, the degumming factor is sodium polyacrylate, the filler is calcium carbonate, the defoamer is BYK-111, and the anti-settling agent is fumed silica; in the component B, the polythiol is 3800, the modified amine is polyamide 650, the accelerator is DMP-30, the diluent is 622, the filler is calcium carbonate, the defoamer is BYK-111, and the anti-settling agent is fumed silica.

[0011] In a third aspect, the present invention further discloses a method for preparing an epoxy adhesive, the method comprising the following steps: By weight, 40-50 parts of epoxy resin, 5-10 parts of sodium polyacrylate, 30-50 parts of calcium carbonate, 0.1-0.5 parts of BYK-111, and 0-0.5 parts of fumed silica are stirred and mixed uniformly, and the temperature is not higher than 60° C. during the stirring process. After stirring uniformly, the mixture is ground using a three-roll mill, evacuated to remove bubbles, and packaged to obtain component A, wherein the epoxy resin is a carbon dioxide-based epoxy resin prepared by the method according to any one of claims 1 to 5; In parts by weight, 10-15 parts of polythiol 3800, 25-30 parts of polyamide 650, 0.5-3 parts of accelerator DMP-30, 5-10 parts of diluent 622, 0.1-0.5 parts of BYK-111 and 0-0.5 parts of fumed silica are stirred and mixed uniformly. The temperature is not higher than 60° C. during the stirring process. After stirring uniformly, the mixture is ground using a three-roll mill, evacuated to remove bubbles, and packaged to obtain component B.

[0012] Preferably, in the above method, 45 parts of epoxy resin, 5 parts of sodium polyacrylate, 35 parts of calcium carbonate, 0.1 parts of BYK-111 and 0.5 parts of fumed silica are stirred and mixed uniformly by weight, and the temperature is not higher than 60° C. during the stirring process. After stirring uniformly, the mixture is ground using a three-roll mill, evacuated to remove bubbles, and packaged to obtain component A, wherein the epoxy resin is a carbon dioxide-based epoxy resin prepared by the method described above; By weight, 15 parts of polythiol 3800, 30 parts of polyamide 650, 2 parts of accelerator DMP-30, 5 parts of diluent 622, 0.1 parts of BYK-111 and 0.5 parts of fumed silica were stirred and mixed uniformly. The temperature was not higher than 60° C. during the stirring process. After stirring uniformly, the mixture was ground using a three-roll mill, evacuated to remove bubbles, and packaged to obtain component B.

[0013] In a fourth aspect, the present invention provides a method for using the epoxy adhesive as described above, wherein component A and component B are mixed to form glue before use, which is applied to the surface of the object to be bonded, the two objects are docked and a certain pressure is applied until the glue is completely cured.

[0014] Compared with the prior art, the present invention has the following beneficial effects: the carbon dioxide-based polyol is a polymer containing two terminal hydroxyl groups generated by the copolymerization reaction of CO2 and propylene oxide. Since the epoxide itself will also undergo self-polymerization in addition to the copolymerization of CO2 and epoxide during the polymerization process, the polymer presents a random block of polycarbonate and polyether. The use of carbon dioxide-based polyols to replace traditional polyols, on the one hand, traditional polyols are derived from fossil raw materials, while carbon dioxide-based polyols are synthesized from carbon dioxide and can consume carbon dioxide, so reducing the use of traditional polyols can reduce carbon emissions, and on the other hand, carbon dioxide-based polyesters have multiple carbonyl structures and ether structures on the main chain in structure, so the epoxy resin obtained has better strength and adhesive properties.

[0015] The epoxy adhesive of the present invention is used as a stick adhesive when slicing silicon blocks. Its excellent strength and adhesive properties make it more suitable for the thin-film development of the photovoltaic slicing industry, ensuring the yield and efficiency of silicon wafer production. DETAILED DESCRIPTION

[0016] The technical solution of the present invention will be clearly and completely described below in conjunction with the specific embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0017] In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "front end", "rear end", "two ends", "one end", "the other end" and the like indicating the orientation or positional relationship are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0018] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0019] Example 1 Synthesis of carbon dioxide based epoxy resin In a dry 500mL three-necked flask, 170g (0.5mol) of carbon dioxide-based polyol (purchased from Hefei Puli Advanced Materials Technology Co., Ltd. PCE230D) and 277.5g (3mol) of epichlorohydrin (purchased from Aladdin AR grade) were added in sequence. Turn on the stirring device to mix the reaction system evenly and control the temperature at 30°C. Then, slowly drip an aqueous solution containing 100g of 40wt% (1mol) sodium hydroxide (purchased from Aladdin AR grade), and the dripping time is controlled to about 1.5 hours. During the dripping process, continue stirring and keep the temperature of the reaction system at 30-35°C. After the dripping is completed, the reaction temperature is slowly raised to 60°C and the reaction is continued for 6 hours. During the reaction, the reaction progress is monitored by thin layer chromatography (TLC). When the carbon dioxide-based polyol raw material point disappears, it indicates that the reaction is basically completed.

[0020] After the reaction is completed, the reaction solution is transferred to a separatory funnel, allowed to stand for stratification, and the lower aqueous phase is separated. The organic phase is first washed with purified water three times, each time with 100 mL of water, to remove the unreacted alkali and the generated salt. Then, the excess epichlorohydrin is removed by a rotary evaporator at 60°C and a vacuum degree of -0.09 MPa to obtain a light yellow viscous liquid.

[0021] Example 2 Preparation of epoxy adhesive The electromagnetically debondable adhesive stick comprises the following raw materials in parts by weight: Component A, including 45 parts of synthetic epoxy resin, 5 parts of degumming factor, 35 parts of filler, 0.1 parts of defoaming agent, and 0.5 parts of anti-settling agent; Component B, including 15 parts of polythiol, 30 parts of modified amine, 2 parts of accelerator DMP-30, 5 parts of diluent, 0.1 parts of defoamer, and 0.5 parts of anti-settling agent; The epoxy resin of component A is synthesized by Example 1, the degumming agent is sodium polyacrylate, the filler is calcium carbonate, the defoamer is BYK-111, and the anti-settling agent is fumed silica; In component B, the polythiol is 3800, the modified amine is polyamide 650, the diluent is 622, the filler is calcium carbonate, the defoamer is BYK-111, and the anti-settling agent is fumed silica.

[0022] Among them, the polythiol 3800 and polyamide 650 used were purchased from Zhuoben New Materials; the representative substance of diluent 622 was 1,4-butanediol diglycidyl ether, which was purchased from Kain Chemical; and the defoamer BYK-111 was purchased from BYK Chemical.

[0023] The preparation method is as follows: 45 parts of synthetic epoxy resin, 5 parts of sodium polyacrylate, 35 parts of calcium carbonate, 0.1 parts of BYK-111 and 0.5 parts of fumed silica were stirred and mixed uniformly by a high-speed disperser, and the temperature was not higher than 60° C. during the stirring process. After stirring uniformly, the mixture was ground by a three-roll mill, evacuated to remove bubbles, and packaged to obtain component A; 15 parts of polythiol 3800, 30 parts of polyamide 650, 2 parts of accelerator DMP-30, 5 parts of diluent 622, 0.1 parts of BYK-111 and 0.5 parts of fumed silica were stirred and mixed uniformly by a high-speed disperser at a temperature not higher than 60° C. After being stirred uniformly, the mixture was ground by a three-roll mill, evacuated to remove bubbles and packaged to obtain component B; How to use: Mix component A and component B in a mass ratio of 1:1 and stir evenly, apply to the surface of the object to be bonded, butt the two objects together, and apply a certain amount of pressure until the glue is completely cured.

[0024] Comparative Example 1 Preparation of epoxy adhesive The electromagnetically debondable adhesive stick comprises the following raw materials in parts by weight; Component A, including 45 parts of epoxy resin, 5 parts of degumming factor, 35 parts of filler, 0.1 parts of defoaming agent, and 0.5 parts of anti-settling agent; Component B, including 15 parts of polythiol, 30 parts of modified amine, 2 parts of accelerator DMP-30, 5 parts of diluent, 0.1 parts of defoamer, and 0.5 parts of anti-settling agent; The epoxy resin of component A is the conventional epoxy resin E-51 on the market, the degumming factor is sodium polyacrylate, the filler is calcium carbonate, the defoamer is BYK-111, and the anti-settling agent is fumed silica; In component B, the polythiol is 3800, the modified amine is polyamide 650, the diluent is 622, the filler is calcium carbonate, the defoamer is BYK-111, and the anti-settling agent is fumed silica; The preparation method is as follows: 45 parts of epoxy resin E-51, 5 parts of sodium polyacrylate, 35 parts of calcium carbonate, 0.1 parts of BYK-111 and 0.5 parts of fumed silica were stirred and mixed uniformly by a high-speed disperser at a temperature not higher than 60° C. After being stirred uniformly, the mixture was ground by a three-roll mill, evacuated to remove bubbles and packaged to obtain component A; 15 parts of polythiol 3800, 30 parts of polyamide 650, 2 parts of accelerator DMP-30, 5 parts of diluent 622, 0.1 parts of BYK-111 and 0.5 parts of fumed silica were stirred and mixed uniformly by a high-speed disperser at a temperature not higher than 60° C. After being stirred uniformly, the mixture was ground by a three-roll mill, evacuated to remove bubbles and packaged to obtain component B; How to use: Mix component A and component B in a mass ratio of 1:1 and stir evenly, apply to the surface of the object to be bonded, butt the two objects together, and apply a certain amount of pressure until the glue is completely cured.

[0025] The epoxy adhesives prepared according to Example 2 and Comparative Example 1 were tested and compared, and the results are shown in Table 1 below: Table 1

[0026] Conclusion: Under the same preparation process conditions, Example 2 and Comparative Example 1 have the same time to reach the maximum bonding strength, which meets the bonding time requirements for photovoltaic slices; the epoxy adhesive obtained by using the carbon dioxide-based epoxy resin of the present invention has increased bonding strength and higher hardness, which can better ensure that there will be no chip drop, edge collapse and other problems during the slicing process.

[0027] The epoxy adhesive prepared according to Example 2 and Comparative Example 1 was used as a stick adhesive for photovoltaic slicing, and the degumming performance was compared. The boiling temperature during degumming was 65° C.-70° C. The results are shown in Table 2 below: Table 2

[0028] Conclusion: As shown in Table 2, the electromagnetic degumming test was carried out simultaneously with Example 2 and Comparative Example 1, and it was found that the product of the present invention can be completely degummed within 300 seconds without any residue.

[0029] The above results show that the product of the present invention can complete the replacement of resin in photovoltaic water-boiling debonding adhesive sticks, and at the same time can improve the adhesion and hardness requirements of adhesive stick products, and is more suitable for the thin-film development of the photovoltaic slicing industry, ensuring the yield and efficiency of silicon wafer production.

[0030] The matters not described in detail in the present invention are all known technologies to those skilled in the art.

[0031] Finally, it should be noted that the above specific implementation methods are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified and replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A method for preparing a carbon dioxide-based epoxy resin, characterized in that: The method comprises adding carbon dioxide-based polyol and epichlorohydrin in a reaction system in proportion, reacting in a solvent in the presence of a base, and separating to obtain a carbon dioxide-based epoxy resin.

2. The method according to claim 1, characterized in that The carbon dioxide-based polyol used has a carbon dioxide content of 10-40 wt%, a carbonate unit content of 30-70 wt%, a hydroxyl value of 37-56 mg KOH / g, and a viscosity of 6000-11000 mPas / 70°C.

3. The method according to claim 2, characterized in that In the reaction system, the molar ratio of the carbon dioxide-based polyol to epichlorohydrin is between 1:6 and 1:10, and 30 to 50 wt% of sodium hydroxide or potassium hydroxide is added as a catalyst, the amount of alkali used is 1 to 3 times the hydroxyl value, and excess epichlorohydrin serves as a solvent. The reaction process is first stirred at 20 to 40° C. for 2 to 5 hours and then heated to reflux for 3 hours.

4. An epoxy adhesive, characterized in that: The adhesive comprises component A and component B, wherein component A comprises 40-50 parts of epoxy resin, 5-10 parts of degumming factor, 30-50 parts of filler, 0.1-0.5 parts of defoamer, and 0-0.5 parts of anti-settling agent in parts by weight; component B comprises 10-15 parts of polythiol, 25-30 parts of modified amine, 0.5-3 parts of accelerator, 5-10 parts of diluent, 0.1-0.5 parts of defoamer, and 0-0.5 parts of anti-settling agent in parts by weight, wherein the epoxy resin is a carbon dioxide-based epoxy resin prepared by the method as described in any one of claims 1 to 3.

5. The epoxy adhesive according to claim 4, characterized in that In the component A, the degumming factor is sodium polyacrylate, the filler is calcium carbonate, the defoamer is BYK-111, and the anti-settling agent is fumed silica; in the component B, the polythiol is 3800, the modified amine is polyamide 650, the accelerator is DMP-30, the diluent is 622, the filler is calcium carbonate, the defoamer is BYK-111, and the anti-settling agent is fumed silica.

6. A method for preparing an epoxy adhesive, characterized in that: The method comprises the following steps: By weight, 40-50 parts of epoxy resin, 5-10 parts of sodium polyacrylate, 30-50 parts of calcium carbonate, 0.1-0.5 parts of BYK-111, and 0-0.5 parts of fumed silica are stirred and mixed uniformly, and the temperature is not higher than 60° C. during the stirring process. After stirring uniformly, the mixture is ground using a three-roll mill, evacuated to remove bubbles, and packaged to obtain component A, wherein the epoxy resin is a carbon dioxide-based epoxy resin prepared by the method according to any one of claims 1 to 5; In parts by weight, 10-15 parts of polythiol 3800, 25-30 parts of polyamide 650, 0.5-3 parts of accelerator DMP-30, 5-10 parts of diluent 622, 0.1-0.5 parts of BYK-111 and 0-0.5 parts of fumed silica are stirred and mixed uniformly. The temperature is not higher than 60° C. during the stirring process. After stirring uniformly, the mixture is ground using a three-roll mill, evacuated to remove bubbles, and packaged to obtain component B.

7. The method for using the epoxy adhesive according to any one of claims 4 to 6, characterized in that: Before use, mix component A and component B to form glue, apply it to the surface of the object to be bonded, butt the two objects together and apply a certain amount of pressure until the glue is completely cured.

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