A resin, its preparation method and application

Abstract

The present invention provides a resin, a preparation method thereof and an application. The preparation method includes: a first reaction is carried out between monomer A and a first diol to obtain a carboxyl-terminated resin; the monomer A includes an unsaturated dibasic acid and / or an unsaturated anhydride; a second reaction is carried out between the carboxyl-terminated resin and a second diol to obtain a third diol; a third reaction is carried out between a diisocyanate and a blocking agent to obtain a semi-blocked isocyanate; a fourth reaction is carried out between the third diol and the semi-blocked isocyanate to obtain a polyurethane resin; a fifth reaction is carried out between the polyurethane resin and a mono-terminally hydrogen-containing silicone oil to obtain the resin. The resin prepared by using the preparation method provided by the present invention can be used as a dispersant for a conductive paste, and can achieve a good dispersion effect on the conductive filler in the conductive paste. At the same time, while improving the conductivity of the conductive paste, it can also reduce the viscosity of the conductive paste, making it more conducive to printing.

Description

Technical Field

[0001] The present invention belongs to the technical field of solar cells, and particularly relates to a resin, a preparation method thereof, and an application thereof. Background Art

[0002] Solar energy is one of the important renewable clean energies. Due to its characteristics of being pollution-free, renewable, and having a large storage capacity, it has broad development prospects. A solar cell is an electronic device that converts light energy into electrical energy using the photovoltaic effect, and it is one of the most promising new power sources among various power sources. Among them, conductive paste is a key raw material for manufacturing solar cells.

[0003] In the perovskite stacked heterojunction conductive paste, due to the high content of conductive fillers, generally the addition amount of conductive fillers is 88 - 94%, so the requirement for the dispersion effect of conductive fillers is particularly high. CN116665948A discloses a low-temperature silver paste for HJT solar cells, including: silver powder accounting for 92% of the total mass of the silver paste, organic carrier accounting for 7.2% of the total mass of the silver paste, coupling agent accounting for 0.2% of the total mass of the silver paste, dispersant accounting for 0.3% of the total mass of the silver paste, curing agent accounting for 0.3% of the total mass of the silver paste, and the dispersant is polyphosphate ester BYK110; CN115579171A discloses an easily weldable low-temperature silver paste for solar cells, including the following components: 85 - 92% of silver powder, 3 - 8% of resin, 3 - 8% of organic solvent, 0.2 - 1.5% of curing agent, 0.2 - 1% of dispersant, 0.5 - 2% of adhesion promoter, and the dispersant includes one or more of polyester and polyurethane.

[0004] Although the existing dispersants have a certain degree of wettability for conductive fillers to a certain extent and can reduce the viscosity of the conductive paste after three-roll milling, during long-term storage, there will still be problems of uneven dispersion of conductive fillers, and in addition, it will also affect the electrical properties of the conductive paste. Therefore, there is an urgent need to provide a dispersant that has a good dispersion effect on conductive fillers, can improve the conductive performance of the conductive paste, and reduce the viscosity of the conductive paste. Summary of the Invention

[0005] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a resin, a preparation method thereof, and an application thereof. Through the design of raw materials and processes, the obtained resin can be used as a dispersant for conductive paste, which can have a good dispersion effect on the conductive fillers in the conductive paste, and while improving the conductive performance of the conductive paste, it can also reduce the viscosity of the conductive paste, making it more conducive to printing.

[0006] To achieve this purpose, the present invention adopts the following technical solutions:

[0007] In the first aspect, the present invention provides a preparation method of a resin, and the preparation method includes:

[0008] Monomer A reacts with a first diol in a first reaction to obtain a carboxyl-terminated resin; the monomer A includes an unsaturated dibasic acid and / or an unsaturated acid anhydride;

[0009] The carboxyl-terminated resin reacts with a second diol in a second reaction to obtain a third diol;

[0010] A diisocyanate reacts with a blocking agent in a third reaction to obtain a semi-blocked isocyanate;

[0011] The third diol reacts with the semi-blocked isocyanate in a fourth reaction to obtain a polyurethane resin;

[0012] The polyurethane resin reacts with a hydrogen-containing silicone oil with one end in a fifth reaction to obtain the resin.

[0013] The resin provided by the present invention has a non-polar conventional resin segment in the main chain segment, which enhances the binding ability with other resin components in the conductive paste. A large number of organosilicon segments are introduced through a hydrosilylation reaction, so that the resin has a comb-like structure. In addition, the organosilicon segments can increase the wetting effect on the conductive filler in the conductive paste, thereby achieving a good dispersion effect on the conductive filler. While improving the conductivity of the conductive paste, the viscosity of the conductive paste can also be reduced, making it more conducive to printing. After the conductive paste using the resin provided by the present invention is printed and baked at a temperature exceeding 100 °C, the -NCO group can be released in the presence of active hydrogen and further crosslinked with other resin components in the conductive paste, thus becoming a part of other resin components. After long-term storage, the conductive paste using the resin provided by the present invention still has a good dispersion effect on the conductive filler.

[0014] The following are the preferred technical solutions of the present invention, but do not limit the technical solutions provided by the present invention. Through the following preferred technical solutions, the purpose and beneficial effects of the present invention can be better achieved and realized.

[0015] As a preferred technical solution, the unsaturated dibasic acid includes maleic acid.

[0016] Preferably, the unsaturated acid anhydride includes maleic anhydride and / or tetrahydrophthalic anhydride.

[0017] Preferably, the first diol includes any one or at least two combinations of diethylene glycol, dipropylene glycol, 1,6-hexanediol, polyethylene glycol or polypropylene glycol, and further preferably diethylene glycol and / or dipropylene glycol.

[0018] Preferably, the number average molecular weight of the polyethylene glycol and polypropylene glycol is independently 200-400, and can be, for example, 220, 240, 260, 280, 300, 320, 340, 360, 380, etc.

[0019] Preferably, the molar ratio of the first diol to monomer A is (1 - 1.1):1, for example, it can be 1.01:1, 1.02:1, 1.03:1, 1.04:1, 1.05:1, 1.06:1, 1.07:1, 1.08:1, 1.09:1, etc.

[0020] Preferably, the temperature of the first reaction is 80 - 100 °C, for example, it can be 82 °C, 84 °C, 86 °C, 88 °C, 90 °C, 92 °C, 94 °C, 96 °C, 98 °C, etc.

[0021] Preferably, the time of the first reaction is 4 - 10 h, for example, it can be 4.5 h, 5 h, 5.5 h, 6 h, 6.5 h, 7 h, 7.5 h, 8 h, 8.5 h, 9 h, 9.5 h, etc.

[0022] Preferably, the first reaction is carried out in the presence of a catalyst and / or an inhibitor.

[0023] Preferably, the catalyst includes p-toluenesulfonic acid and / or dodecylbenzenesulfonic acid.

[0024] Preferably, based on the total mass of monomer A and the first diol being 100%, the mass of the catalyst is 0.4 - 0.8%, for example, it can be 0.42%, 0.45%, 0.48%, 0.5%, 0.52%, 0.55%, 0.58%, 0.6%, 0.62%, 0.65%, 0.68%, 0.7%, 0.72%, 0.75%, 0.78%, etc.

[0025] Preferably, the inhibitor includes dibutylhydroxytoluene.

[0026] Preferably, based on the total mass of monomer A and the first diol being 100%, the mass of the inhibitor is 0.1 - 0.2%, for example, it can be 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, etc.

[0027] Preferably, dry air is continuously introduced during the progress of the first reaction.

[0028] Preferably, the second diol includes any one or a combination of at least two of 1,3-propanediol, 1,4-butanediol, or 1,6-hexanediol.

[0029] Preferably, the molar ratio of the carboxyl group of the terminal carboxyl resin to the hydroxyl group of the second diol is 1:(1.2 - 1.5), and can be, for example, 1:1.22, 1:1.25, 1:1.28, 1:1.3, 1:1.32, 1:1.35, 1:1.38, 1:1.4, 1:1.42, 1:1.45, 1:1.48, etc.

[0030] Preferably, the temperature of the second reaction is 105 - 115 °C, and can be, for example, 106 °C, 107 °C, 108 °C, 109 °C, 110 °C, 111 °C, 112 °C, 113 °C, 114 °C, etc.

[0031] Preferably, the second reaction ends when the acid value of the reaction system is less than 5 mgKOH / g (such as 4.5 mgKOH / g, 4.2 mgKOH / g, 4 mgKOH / g, 3.5 mgKOH / g, 3.2 mgKOH / g, 3 mgKOH / g, 2.5 mgKOH / g, 2.2 mgKOH / g, 2 mgKOH / g, 1.5 mgKOH / g, 1.2 mgKOH / g, 1 mgKOH / g, 0.5 mgKOH / g, 0.2 mgKOH / g, etc.).

[0032] Preferably, the hydroxyl value of the third diol is 60 - 150 mgKOH / g, and can be, for example, 62 mgKOH / g, 64 mgKOH / g, 66 mgKOH / g, 68 mgKOH / g, 70 mgKOH / g, 72 mgKOH / g, 74 mgKOH / g, 76 mgKOH / g, 78 mgKOH / g, 80 mgKOH / g, 82 mgKOH / g, 84 mgKOH / g, 86 mgKOH / g, 88 mgKOH / g, 90 mgKOH / g, 92 mgKOH / g, 94 mgKOH / g, 95 mgKOH / g, 100 mgKOH / g, 105 mgKOH / g, 110 mgKOH / g, 115 mgKOH / g, 120 mgKOH / g, 125 mgKOH / g, 130 mgKOH / g, 135 mgKOH / g, 140 mgKOH / g, 145 mgKOH / g, etc.

[0033] Preferably, the diisocyanate includes any one or a combination of at least two of isophthalic diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, or dicyclohexylmethane diisocyanate.

[0034] Preferably, the blocking agent includes glycerol carbonate and / or diisopropylamine.

[0035] Preferably, the molar ratio of the sealant to the diisocyanate is 1:(2 - 4), and for example, it can be 1:2.2, 1:2.4, 1:2.6, 1:2.8, 1:3, 1:3.2, 1:3.4, 1:3.6, 1:3.8, etc.

[0036] Preferably, the temperature of the third reaction is 70 - 78 °C, and for example, it can be 70.5 °C, 71 °C, 71.5 °C, 72 °C, 72.5 °C, 73 °C, 73.5 °C, 74 °C, 74.5 °C, 75 °C, 75.5 °C, 76 °C, 76.5 °C, 77 °C, 77.5 °C, etc.

[0037] Preferably, the time of the third reaction is 6 - 12 h, and for example, it can be 6.5 h, 7 h, 7.5 h, 8 h, 8.5 h, 9 h, 9.5 h, 10 h, 10.5 h, 11 h, 11.5 h, etc.

[0038] Preferably, the third reaction is carried out in the presence of an organic amine catalyst.

[0039] Exemplarily, the organic amine catalyst can be purchased from organic amine catalysts of Tosoh Corporation of Japan and Evonik Industries AG.

[0040] Preferably, based on the mass of the diisocyanate being 100%, the mass of the organic amine catalyst is 0.05 - 0.2%, and for example, it can be 0.06%, 0.08%, 0.1%, 0.12%, 0.14%, 0.16%, 0.18%, etc.

[0041] Preferably, the molar ratio of the third diol to the semi-blocked isocyanate is (1 - 1.05):1, and for example, it can be 1.01:1, 1.02:1, 1.03:1, 1.04:1, etc.

[0042] Preferably, the temperature of the fourth reaction is 60 - 75 °C, and for example, it can be 62 °C, 64 °C, 66 °C, 68 °C, 70 °C, 72 °C, 74 °C, etc.

[0043] Preferably, the time of the fourth reaction is 10 - 18 h, and for example, it can be 10.5 h, 11 h, 11.5 h, 12 h, 12.5 h, 13 h, 13.5 h, 14 h, 14.5 h, 15 h, 15.5 h, 16 h, 16.5 h, 17 h, 17.5 h, etc.

[0044] Preferably, after the fourth reaction, it further includes a purification treatment step.

[0045] Preferably, the purification method includes: washing the reaction product with ether 2-3 times, and then removing the ether by vacuum distillation at 80 °C to obtain a polyurethane resin with higher purity.

[0046] Preferably, the number-average molecular weight of the hydrogen-terminated silicone oil is 500-800, and can be, for example, 520, 540, 560, 580, 600, 620, 640, 660, 680, 700, 720, 740, 760, 780, etc.

[0047] Preferably, the mass ratio of the polyurethane resin to the hydrogen-terminated silicone oil is 100:(10-18), and can be, for example, 100:10.5, 100:11, 100:11.5, 100:12, 100:12.5, 100:13, 100:13.5, 100:14, 100:14.5, 100:15, 100:15.5, 100:16, 100:16.5, 100:17, 100:17.5, etc.

[0048] Preferably, the temperature of the fifth reaction is 90-110 °C, and can be, for example, 92 °C, 94 °C, 96 °C, 98 °C, 100 °C, 102 °C, 104 °C, 106 °C, 108 °C, etc.

[0049] Preferably, the time of the fifth reaction is 6-10 h, and can be, for example, 6.2 h, 6.5 h, 6.8 h, 7 h, 7.2 h, 7.5 h, 7.8 h, 8 h, 8.2 h, 8.5 h, 8.8 h, 9 h, 9.2 h, 9.5 h, 9.8 h, etc.

[0050] Preferably, the fifth reaction is carried out in the presence of a Karstedt catalyst.

[0051] Preferably, based on the mass of the hydrogen-terminated silicone oil being 100%, the mass of the Karstedt catalyst is 0.03-0.05%, and can be, for example, 0.032%, 0.034%, 0.036%, 0.038%, 0.04%, 0.042%, 0.044%, 0.046%, 0.048%, etc.

[0052] Preferably, the fifth reaction is carried out in an organic solvent.

[0053] Preferably, the organic solvent includes ethylene glycol monobutyl ether acetate and / or diethylene glycol monobutyl ether acetate.

[0054] Preferably, based on the total mass of the polyurethane resin and the hydrogen-terminated silicone oil being 100%, the mass of the organic solvent is 30-40%, and can be, for example, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, etc.

[0055] Preferably, the preparation method specifically includes the following steps:

[0056] (1) Monomer A, the first diol, a catalyst, and an inhibitor are reacted at 80 - 100 °C for 4 - 10 h to obtain a carboxyl - terminated resin, and dry air is continuously introduced during the reaction process; the monomer A includes unsaturated dibasic acid and / or unsaturated anhydride; the molar ratio of the first diol to monomer A is (1 - 1.1):1; based on the total mass of monomer A and the first diol being 100%, the mass of the catalyst is 0.4 - 0.8%, and the mass of the inhibitor is 0.1 - 0.2%;

[0057] (2) The carboxyl - terminated resin and the second diol are reacted under the condition of 105 - 115 °C until the acid value of the reaction system is less than 5 mgKOH / g, and a third diol with a hydroxyl value of 60 - 150 mgKOH / g is obtained; the molar ratio of the carboxyl group of the carboxyl - terminated resin to the hydroxyl group of the second diol is 1:(1.2 - 1.5);

[0058] (3) Diisocyanate, a blocking agent, and an organic amine catalyst are reacted at 70 - 78 °C for 6 - 12 h to obtain a semi - blocked isocyanate; the molar ratio of the blocking agent to diisocyanate is 1:(2 - 4); based on the mass of diisocyanate being 100%, the mass of the organic amine catalyst is 0.05 - 0.2%;

[0059] (4) The third diol and the semi - blocked isocyanate are reacted under the condition of 60 - 75 °C for 10 - 18 h. After the reaction product is washed 2 - 3 times with ether, ether is removed by vacuum distillation at 80 °C to obtain a polyurethane resin; the molar ratio of the third diol to the semi - blocked isocyanate is (1 - 1.05):1;

[0060] (5) The polyurethane resin, mono - terminal hydrogen - containing silicone oil, Karstedt catalyst, and an organic solvent are reacted under the condition of 90 - 110 °C for 6 - 10 h to obtain the resin; the mass ratio of the polyurethane resin to the mono - terminal hydrogen - containing silicone oil is 100:(10 - 18); based on the total mass of the polyurethane resin and the mono - terminal hydrogen - containing silicone oil being 100%, the mass of the organic solvent is 30 - 40%; based on the mass of the mono - terminal hydrogen - containing silicone oil being 100%, the mass of the Karstedt catalyst is 0.03 - 0.05%.

[0061] Second, the present invention provides a resin, and the resin is prepared by using the preparation method as described in the first aspect.

[0062] Third, the present invention provides a conductive paste, and the conductive paste includes the resin as described in the second aspect.

[0063] Preferably, the mass percentage of the resin as described in the second aspect in the conductive paste is 1-1.5%, and can be, for example, 1.05%, 1.1%, 1.15%, 1.2%, 1.25%, 1.3%, 1.35%, 1.4%, 1.45%, etc.

[0064] Preferably, the conductive paste further comprises a conductive filler; the conductive filler includes any one or a combination of at least two of copper powder, silver powder or silver-coated copper powder.

[0065] Fourthly, the present invention provides an application of the conductive paste as described in the third aspect in a perovskite stacked heterojunction solar cell.

[0066] Compared with the prior art, the present invention has the following beneficial effects:

[0067] The resin prepared by using the preparation method provided by the present invention can be used as a dispersant for the conductive paste, which can increase the wetting effect on the conductive filler in the conductive paste, thereby achieving a good dispersion effect on the conductive filler, and while improving the conductivity of the conductive paste, it can also reduce the viscosity of the conductive paste, making it more conducive to printing; in addition, after the conductive paste using the resin provided by the present invention is printed, when the baking temperature exceeds 100 °C, the resin provided by the present invention can release -NCO groups in the presence of active hydrogen and further crosslink with other resin components in the conductive paste, thus becoming a part of other resin components. The initial viscosity of the conductive paste using the resin provided by the present invention as a dispersant is 13-42 Pa·s at 25 °C, and the viscosity is 18-51 Pa·s after standing for 72 h; after the conductive paste is printed, the initial line resistance is 353-880 Ω, and the line resistance after standing for 72 h is 367-960 Ω. Description of the Drawings

[0068] Figure 1 is the infrared spectrum of the terminal carboxyl resin in Example 1;

[0069] Figure 2 is the infrared spectrum of the third diol in Example 1;

[0070] Figure 3 is the infrared spectrum of the semi-blocked isocyanate in Example 1;

[0071] Figure 4 is the infrared spectrum of the polyurethane resin in Example 1;

[0072] Figure 5 is the infrared spectrum of the resin provided in Example 1. Detailed Embodiments

[0073] The technical solution of the present invention will be further described below in conjunction with the accompanying drawings and through specific embodiments. Those skilled in the art should understand that the embodiments are only for helping to understand the present invention and should not be regarded as specific limitations on the present invention.

[0074] The sources of some components in the following examples and comparative examples are as described below:

[0075] (1) Organic amine catalyst: Purchased from Tosoh Corporation, Japan, L33B;

[0076] (2) Monoterminal hydrogen-containing silicone oil: The following monoterminal hydrogen-containing silicone oils are all purchased from Siwansi Materials Technology (Nantong) Co., Ltd.;

[0077] Monoterminal hydrogen-containing silicone oil A, with a number average molecular weight of 500;

[0078] Monoterminal hydrogen-containing silicone oil B, with a number average molecular weight of 600;

[0079] Monoterminal hydrogen-containing silicone oil C, with a number average molecular weight of 800;

[0080] Monoterminal hydrogen-containing silicone oil D, with a number average molecular weight of 400;

[0081] Monoterminal hydrogen-containing silicone oil E, with a number average molecular weight of 1200;

[0082] (3) Karstedt catalyst: Purchased from Zhende Chemical Industry, with a platinum content of 1000 ppm.

[0083] In the following examples and comparative examples, the acid value of the reaction system was tested by acid-base titration; the hydroxyl value of the third diol was tested according to GBT 7193.2-1987 "Determination Method of Hydroxyl Value for Unsaturated Polyester Resins".

[0084] In Example 1, the infrared spectra of each substance were obtained by testing with a Fourier transform infrared spectrometer (manufacturer: Thermo Fisher, model: Summit X).

[0085] Example 1

[0086] A resin and its preparation method, the preparation method comprising the following steps:

[0087] (1) 1 mol of maleic anhydride, 1 mol of diethylene glycol, 1.2 g of p-toluenesulfonic acid and 0.3 g of dibutylhydroxytoluene were reacted at 90 °C for 6 h, and dry air was continuously introduced during the reaction to obtain a carboxyl-terminated resin; the infrared spectrum of the carboxyl-terminated resin is as Figure 1 shown. It can be seen from the figure that 1740 cm -1 is the characteristic absorption peak of C=O in the carboxyl group, and 3425 cm -1 is the characteristic absorption peak of O-H in the carboxyl group;

[0088] (2) 1 mol of the terminal carboxyl resin reacts with 1.2 mol of 1,3-propanediol at 105 °C until the acid value of the reaction system is less than 5 mg KOH / g, and then the reaction ends to obtain a third diol with a hydroxyl value of 75 mg KOH / g; the infrared spectrum of the third diol is as follows Figure 2 shown. It can be seen from the figure that the terminal carboxyl resin reacts with 1,3-propanediol to form a third diol;

[0089] (3) 2 mol of isophthalic dimethyl diisocyanate, 1 mol of glycerol carbonate, and 0.3 g of organic amine catalyst react at 70 °C for 6 h to obtain a semi-blocked isocyanate; the infrared spectrum of the semi-blocked isocyanate is as follows Figure 3 shown. It can be seen from the figure that the characteristic absorption peak at 2260 cm -1 is the characteristic absorption peak of the -NCO group, and the characteristic absorption peak at 3350 cm -1 is the characteristic absorption peak of N-H, which proves that the semi-blocked isocyanate is prepared;

[0090] (4) After 1 mol of the third diol reacts with 1 mol of the semi-blocked isocyanate at 65 °C for 10 h, the reaction product is washed twice with ether, and then the ether is removed by vacuum distillation at 80 °C to obtain a polyurethane resin; the infrared spectrum of the polyurethane resin is as follows Figure 4 shown. It can be seen from the figure that the characteristic absorption peak of -NCO disappears, indicating that a polyurethane resin is formed;

[0091] (5) 100 parts by weight of the polyurethane resin, 14 parts by weight of mono-terminal hydrogen-containing silicone oil A, 0.006 parts by weight of Kaster catalyst, and 35 parts by weight of ethylene glycol monobutyl ether acetate react at 90 °C for 6 h to obtain the resin, and the infrared spectrum of the resin is as follows Figure 5 shown. It can be seen from the figure that the polyurethane resin reacts with mono-terminal hydrogen-containing silicone oil A to form the resin.

[0092] Example 2

[0093] A resin and its preparation method, and the preparation method includes the following steps:

[0094] (1) 1 mol of maleic acid, 1 mol of dipropylene glycol, 1.1 g of dodecylbenzenesulfonic acid, and 0.3 g of dibutylhydroxytoluene react at 90 °C for 8 h, and dry air is continuously introduced during the reaction to obtain a terminal carboxyl resin;

[0095] (2) 1 mol of the terminal carboxyl resin reacts with 1.3 mol of 1,6-hexanediol at 110 °C until the acid value of the reaction system is less than 5 mg KOH / g, and then the reaction ends to obtain a third diol with a hydroxyl value of 102 mg KOH / g;

[0096] (3) 2 mol of isophorone diisocyanate, 1 mol of diisopropylamine, and 0.4 g of organic amine catalyst are reacted at 74 °C for 10 h to obtain semi-blocked isocyanate;

[0097] (4) 1.05 mol of the third diol and 1 mol of the semi-blocked isocyanate are reacted at 75 °C for 18 h, and the reaction product is washed twice with ether, and then the ether is removed by vacuum distillation at 80 °C to obtain a polyurethane resin;

[0098] (5) 100 parts by weight of the polyurethane resin, 10 parts by weight of mono-terminal hydrogen-containing silicone oil B, 0.003 parts by weight of Kaster catalyst, and 40 parts by weight of diethylene glycol butyl ether acetate are reacted at 100 °C for 8 h to obtain the resin.

[0099] Example 3

[0100] A resin and its preparation method, the preparation method comprising the following steps:

[0101] (1) 1 mol of tetrahydrophthalic anhydride, 1.05 mol of dipropylene glycol, 1.5 g of p-toluenesulfonic acid, and 0.5 g of dibutylhydroxytoluene are reacted at 90 °C for 7 h, and dry air is continuously introduced during the reaction to obtain a carboxyl-terminated resin;

[0102] (2) 1 mol of the carboxyl-terminated resin and 1.5 mol of 1,4-butanediol are reacted at 115 °C until the acid value of the reaction system is less than 5 mg KOH / g, and the third diol with a hydroxyl value of 140 mg KOH / g is obtained;

[0103] (3) 4 mol of hexamethylene diisocyanate, 1 mol of glycerol carbonate, and 0.5 g of organic amine catalyst are reacted at 78 °C for 8 h to obtain semi-blocked isocyanate;

[0104] (4) 1.02 mol of the third diol and 1 mol of the semi-blocked isocyanate are reacted at 75 °C for 16 h, and the reaction product is washed three times with ether, and then the ether is removed by vacuum distillation at 80 °C to obtain a polyurethane resin;

[0105] (5) 100 parts by weight of the polyurethane resin, 10 parts by weight of mono-terminal hydrogen-containing silicone oil C, 0.004 parts by weight of Kaster catalyst, and 38 parts by weight of ethylene glycol butyl ether acetate are reacted at 110 °C for 10 h to obtain the resin.

[0106] Example 4

[0107] A resin and its preparation method, which is different from Example 1 only in that in step (1), diethylene glycol is replaced with 1,6-hexanediol in an equimolar amount, and the remaining raw materials, process parameters, and steps are the same as those in Example 1.

[0108] Example 5

[0109] A resin and its preparation method, the difference from Example 1 is only that in step (5), the same mass of monohydrosilane A is replaced with monohydrosilane D, and the remaining raw materials, process parameters and steps are the same as those in Example 1.

[0110] Example 6

[0111] A resin and its preparation method, the difference from Example 1 is only that in step (5), the same mass of monohydrosilane A is replaced with monohydrosilane E, and the remaining raw materials, process parameters and steps are the same as those in Example 1.

[0112] Example 7

[0113] A resin and its preparation method, the difference from Example 1 is only that the dosage of monohydrosilane A in step (5) is 6 parts by weight, and the remaining raw materials, process parameters and steps are the same as those in Example 1.

[0114] Example 8

[0115] A resin and its preparation method, the difference from Example 1 is only that the dosage of monohydrosilane A in step (5) is 22 parts by weight, and the remaining raw materials, process parameters and steps are the same as those in Example 1.

[0116] Example 9

[0117] A resin and its preparation method, the difference from Example 1 is only that the dosage of glycerol carbonate in step (3) is 0.4 mol, and the remaining raw materials, process parameters and steps are the same as those in Example 1.

[0118] The sources of some components in the following application examples and comparative application examples are as follows:

[0119] (1) Curing agent: purchased from Guangzhou Haoyi New Materials Technology Co., Ltd., HF-9069;

[0120] (2) Conductive copper powder: purchased from Jiangsu Boqian, Cu-GB3501N;

[0121] (3) Bisphenol F epoxy resin: purchased from Nan Ya Resins, NPEF-170;

[0122] (4) Polyester resin: purchased from Bostik 3300;

[0123] (5) Dispersant: purchased from BYK Chemie, DISPERBYK-108.

[0124] Application Example 1

[0125] A conductive paste, the components of the conductive paste include 1.3 parts by weight of the resin provided in Example 1, 92 parts by weight of conductive copper powder, 1.8 parts by weight of bisphenol F epoxy resin, 2.5 parts by weight of curing agent HF-9069, 0.8 parts by weight of polyester resin, and 1.6 parts by weight of DBE solvent;

[0126] The preparation method of the conductive paste includes:

[0127] After mixing the above materials, use a three-roll mill to perform three-roll stirring and dispersion to obtain the conductive paste.

[0128] Application Examples 2-9

[0129] A conductive paste and its preparation method, the difference from Application Example 1 is only that the resin provided in Example 1 is replaced with the resin provided in Examples 2-9 in equal mass, and the remaining raw materials, process parameters and steps are the same as those in Application Example 1.

[0130] Comparative Application Example 1

[0131] A conductive paste and its preparation method, the difference from Application Example 1 is only that the resin provided in Example 1 is replaced with the polyurethane resin prepared in step (4) of Example 1 in equal mass, and the remaining raw materials, process parameters and steps are the same as those in Application Example 1.

[0132] Comparative Application Example 2

[0133] A conductive paste and its preparation method, the difference from Application Example 1 is only that the resin provided in Example 1 is replaced with a mixture of 1.2 parts by weight of the polyurethane resin prepared in step (4) of Example 1 and 0.1 part by weight of mono-terminal hydrogen-containing silicone oil A, and the remaining raw materials, process parameters and steps are the same as those in Application Example 1.

[0134] Comparative Application Example 3

[0135] A conductive paste and its preparation method, the difference from Application Example 1 is only that the resin provided in Example 1 is replaced with DISPERBYK-108 in equal mass, and the remaining raw materials, process parameters and steps are the same as those in Application Example 1.

[0136] Performance Test

[0137] (1) Viscosity: Use a rotational viscometer to measure the viscosity value of the conductive paste at 25 °C under a rotational speed of 200 rpm; after the conductive paste is placed for 72 h, measure its viscosity value again;

[0138] (2) Line resistance: Print a serpentine circuit on a transparent glass plate with a line width and line spacing of 2 mm, then bake it at 160 °C for 30 min. After cooling to room temperature, use a resistivity tester (manufacturer: Suzhou Xintonghui, model TH2515) to measure the line resistance of the serpentine circuit board; after placing the serpentine circuit board for 72 h, measure its line resistance again.

[0139] Test the conductive pastes provided in the application examples and comparative application examples according to the above method, and the test results are shown in Table 1 below:

[0140] Table 1

[0141]

[0142] It can be seen from the data in Table 1 that compared with Comparative Application Example 3, the initial viscosities of the conductive pastes provided in Application Examples 1-3 are lower, and the initial line resistances after printing are lower, indicating that the conductive fillers are evenly dispersed in the conductive pastes. After standing for 72 h, both the viscosity and the line resistance are smaller, indicating that the resin provided by the present invention still has a good dispersing effect on the conductive fillers.

[0143] It can be seen from Application Example 4 that replacing the polyether-type diol with a polyester-type diol has little effect on the electrical properties of the conductive paste, but has a greater effect on its viscosity. The reason is that the polyester structure is more rigid and not as easy to rotate as the polyether structure, resulting in a decrease in the viscosity of the conductive paste.

[0144] It can be seen from Application Example 5 that for the resin prepared using a mono-terminal hydrogen-containing silicone oil with a lower number-average molecular weight, the silicone oil chain segment in the resin structure has a lower molecular weight and the dispersion effect is poor, resulting in an increase in the viscosity of the conductive paste and a deterioration of the electrical properties. It can be seen from Application Example 6 that for the resin prepared using a mono-terminal hydrogen-containing silicone oil with a higher number-average molecular weight, the silicone oil chain segment in the resin structure is longer, and the number of comb-like structures decreases under the same mass of the resin, resulting in an increase in the viscosity of the conductive paste and a deterioration of the electrical properties.

[0145] It can be seen from Application Example 7 that if the amount of mono-terminal hydrogen-containing silicone oil is too low, it cannot play the role of wetting the conductive copper powder, resulting in poor dispersion of the resin on the conductive fillers; it can be seen from Application Example 8 that if the addition amount of mono-terminal hydrogen-containing silicone oil is too high, although the dispersion effect of the resin is good and the viscosity stability is good after standing for 72 h, due to the too high proportion of silicone oil in the main chain segment of the resin, and silicone oil is an insulating material, it will cause an increase in the resistance value after printing the conductive paste and reduce its conductive effect.

[0146] It can be seen from Application Example 9 that when the amount of the blocking agent is small, the molecular weight of the resin becomes too large, resulting in an increase in the viscosity of the conductive paste and a poor dispersion effect.

[0147] As can be seen from Comparative Application Example 1, if the polyurethane resin is not modified by hydrosilylation, the dispersion effect of the polyurethane resin on the conductive filler is poor, resulting in a significant increase in the viscosity of the conductive paste and relatively poor electrical properties.

[0148] As can be seen from Comparative Application Example 2, by mixing the polyurethane resin with the mono-terminal hydrogen-containing silicone oil, the dispersion of the conductive filler is uneven, resulting in an increase in the viscosity of the conductive paste and relatively poor electrical properties.

[0149] The applicant declares that the present invention uses the above-mentioned embodiments to illustrate the detailed process equipment and process flow of the present invention, but the present invention is not limited to the above-mentioned detailed process equipment and process flow, that is, it does not mean that the present invention must rely on the above-mentioned detailed process equipment and process flow to be implemented. Those skilled in the art should understand that any improvement to the present invention, the equivalent substitution of each raw material of the product of the present invention, the addition of auxiliary components, the selection of specific methods, etc., all fall within the protection scope and the disclosure scope of the present invention.

Claims

1. A method for preparing a resin, characterized in that, The preparation method includes: Monomer A and a first diol undergo a first reaction to obtain a carboxyl-terminated resin; the monomer A includes an unsaturated dibasic acid and / or an unsaturated anhydride; the molar ratio of the first diol to monomer A is (1 - 1.1):1; The carboxyl-terminated resin and a second diol undergo a second reaction to obtain a third diol; A diisocyanate and a blocking agent undergo a third reaction to obtain a semi-blocked isocyanate; the molar ratio of the blocking agent to the diisocyanate is 1:(2 - 4); The third diol and the semi-blocked isocyanate undergo a fourth reaction to obtain a polyurethane resin; The polyurethane resin and a mono-terminal hydrogen-containing silicone oil undergo a fifth reaction to obtain the resin; the number-average molecular weight of the mono-terminal hydrogen-containing silicone oil is 500 - 800; the mass ratio of the polyurethane resin to the mono-terminal hydrogen-containing silicone oil is 100:(10 - 18).

2. The preparation method according to claim 1, wherein, The unsaturated dibasic acid includes maleic acid; The unsaturated anhydride includes maleic anhydride and / or tetrahydrophthalic anhydride; The first diol includes any one or a combination of at least two of diethylene glycol, dipropylene glycol, 1,6-hexanediol, polyethylene glycol, or polypropylene glycol.

3. The preparation method according to claim 1, characterized in that, The temperature of the first reaction is 80 - 100 °C; The time of the first reaction is 4 - 10 h; The first reaction is carried out in the presence of a catalyst and / or an inhibitor.

4. The preparation method according to claim 1, wherein The second diol includes any one or a combination of at least two of 1,3-propanediol, 1,4-butanediol, or 1,6-hexanediol; The molar ratio of the carboxyl group of the carboxyl-terminated resin to the hydroxyl group of the second diol is 1:(1.2 - 1.5); The temperature of the second reaction is 105 - 115 °C; The second reaction ends when the acid value of the reaction system is less than 5 mgKOH / g; The hydroxyl value of the third diol is 60 - 150 mgKOH / g.

5. The preparation method according to claim 1, characterized in that, The diisocyanate includes any one or a combination of at least two of isophthaloyl diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, or dicyclohexylmethane diisocyanate; The blocking agent includes glycerol carbonate and / or diisopropylamine; The temperature of the third reaction is 70 - 78 °C; The time of the third reaction is 6 - 12 h; The third reaction is carried out in the presence of an organic amine catalyst.

6. The preparation method according to claim 1, wherein The molar ratio of the third diol to the semi-blocked isocyanate is (1 - 1.05):1; The temperature of the fourth reaction is 60 - 75 °C; The time of the fourth reaction is 10 - 18 h.

7. The preparation method according to claim 1, wherein The temperature of the fifth reaction is 90 - 110 °C; The time of the fifth reaction is 6 - 10 h; The fifth reaction is carried out in the presence of a Karstedt catalyst.

8. A resin, characterized in that, The resin is prepared by the preparation method described in any one of claims 1 - 7.

9. A conductive paste, characterized in that, The conductive paste includes the resin described in claim 8.

10. Application of a conductive paste as described in claim 9 in a perovskite stacked heterojunction solar cell.

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