Phosphate modified polyether polyol as well as preparation method and application thereof
By using phosphate-modified polyether polyol as a leveling agent, the problem of migration of leveling dispersants during the silver paste curing process was solved, achieving low ESR and high conductivity in capacitors.
Patent Information
- Application Number
- CN202410614472.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-17
- Publication Date
- 2025-11-18
AI Technical Summary
In the prior art, leveling dispersants tend to migrate to the surface during the silver paste curing process, which increases the interfacial impedance of the capacitor and affects its electrical performance.
Phosphate-modified polyether polyol is used as a leveling agent. By mixing with polyether polyol and carrying out a condensation reaction, adhesive silver paste for capacitors is prepared, which improves the adhesion between the silver paste and the substrate and avoids the migration of the leveling agent.
It improves the leveling and conductivity of silver paste, reduces the equivalent series resistance (ESR) of capacitors, and improves the electrical performance of capacitors.
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Figure CN120965993A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of capacitors, and particularly relates to a phosphate-modified polyether polyol and a preparation method and application thereof. BACKGROUND
[0002] Chip polymer laminated aluminum capacitor (MLPC) is a new type of aluminum electrolytic capacitor. The MLPC uses a high-conductivity polymer material as a cathode, and then is immersed in carbon paste and silver to obtain a unit chip. Then, the unit chip is bonded with the unit chip and the lead frame through bonding silver paste. Finally, the MLPC is obtained by encapsulation through epoxy encapsulation material. With the development of electronic technology and electronic components, low power consumption and high speed processing are the development direction of modern electronic equipment, which puts forward higher requirements for the performance of MLPC capacitors. Among them, MLPC with low ESR is a research hotspot. As an important component, the electrical performance of the bonding silver directly affects the interface impedance between the unit chips and between the unit chip and the lead frame.
[0003] At present, the high-viscosity bonding silver paste for capacitors has requirements for fluidity. The leveling dispersant added in the prior art can improve the fluidity of the silver paste, but the leveling agent is prone to migrate to the surface of the silver layer during the curing process, which causes the problem of reducing the electrical performance (sheet resistance, resistivity or conductivity) of the silver paste, directly leading to the large ESR of the capacitor. SUMMARY
[0004] Therefore, the purpose of the present application is to provide a phosphate-modified polyether polyol and a preparation method and application thereof. The phosphate-modified polyether polyol can effectively improve the leveling property of the silver paste, improve the adhesion of the paste to the substrate, and the bonding silver paste prepared from the raw material can make the capacitor have low ESR.
[0005] To achieve the above purpose, the present application adopts the following technical solutions.
[0006] In a first aspect of the present application, a phosphate-modified polyether polyol is provided, which includes at least one of the compounds shown in the following structural formula I:
[0007]
[0008] wherein R1 and R2 are independently selected from ethyl and propyl, R3 and R4 are independently selected from hydrogen, methyl, ethyl, butyl, glycerol, 2-ethylhexyl and isooctyl, and at least one of R3 and R4 is not hydrogen; a and b are integers, and 5≤a≤100 and 5≤b≤100. a and b represent the degree of polymerization.
[0009] In a second aspect of the present application, a method for preparing the phosphate-modified polyether polyol is provided, comprising the following steps: mixing the polyether polyol with the phosphate uniformly, conducting a condensation reaction at 70-100°C, and distilling the reaction product under reduced pressure to obtain the phosphate-modified polyether polyol.
[0010] In some embodiments, the condensation reaction time is 4-10 hours.
[0011] In some embodiments, the temperature for the distillation under reduced pressure is 90-120°C.
[0012] In some embodiments, the molar ratio of the polyether polyol to the phosphate is (0.8-1.5):(1.0-2.0), which ensures that the phosphate-modified polyether polyol retains an appropriate amount of hydroxyl groups, which is beneficial for improving the adhesion of the slurry to the substrate and avoiding the migration of the additive to the surface of the silver paste, which leads to poor electrical properties. Preferably, the molar ratio is (1.0-1.2):(1.2-1.5).
[0013] In some embodiments, the polyether polyol is selected from at least one of polypropylene glycol ether and polyethylene glycol ether.
[0014] In some embodiments, the phosphate is selected from at least one of mono-phosphate and di-phosphate; the mono-phosphate includes monobutyl phosphate, 2-ethylhexyl phosphate, isooctyl phosphate, and glycerol phosphate; and the di-phosphate includes dimethyl phosphate, diethyl phosphate, and dibutyl phosphate.
[0015] In a third aspect of the present application, the phosphate-modified polyether polyol or the phosphate-modified polyether polyol prepared by the method described above is used in the preparation of an adhesive silver paste for capacitors.
[0016] In a fourth aspect of the present application, an adhesive silver paste for capacitors is provided, which is prepared from the following raw materials by weight: 5-15 parts of resin, 60-80 parts of silver powder, 0.1-1.5 parts of the phosphate-modified polyether polyol according to any one of claims 1-2 or prepared by the method according to any one of claims 3-6, and 10-25 parts of solvent.
[0017] In some embodiments, the resin is selected from at least one of acrylic resin, epoxy resin, chlorovinyl acetate resin, polyurethane resin, and polyester resin.
[0018] In some embodiments, the silver powder is selected from at least one of spherical silver with a particle size of 0.5-10 um and flaky silver with a particle size of 1-15 um, and the surface of the silver powder is treated with oleic acid or stearic acid.
[0019] In some embodiments, the solvent is selected from two or more of butyl acetate, propylene glycol methyl ether acetate, ethylene glycol butyl ether, ethylene glycol butyl ether acetate, diethylene glycol ethyl ether acetate, diethylene glycol butyl ether acetate.
[0020] In a fifth aspect, the application provides a method for preparing the silver paste for capacitor, comprising the following steps: taking raw materials, stirring and dispersing uniformly, then grinding, and finally dispersing and stirring to obtain the silver paste for capacitor.
[0021] In some embodiments, the grinding is performed using a three-roll grinder.
[0022] In a sixth aspect, the application provides a capacitor, raw materials for preparing the capacitor comprising the silver paste as described above.
[0023] In some embodiments, the capacitor is an aluminum capacitor; preferably, the capacitor is a chip polymer laminated aluminum capacitor.
[0024] The application provides a phosphate-modified polyether polyol, which can be used as a leveling agent for preparing a silver paste for capacitor. The introduction of phosphate can improve the compatibility between silver powder and resin in the conductive silver paste, thereby improving the leveling property of the silver paste. Meanwhile, the phosphate-modified polyether has greater adhesion to the substrate, avoiding the migration of the leveling agent to the surface of the conductive film layer during the curing process, which leads to poor electrical properties. The phosphate-modified polyether polyol of the application can be used to prepare a silver paste with good leveling property and high conductivity, and the capacitor prepared therefrom has low ESR. DETAILED DESCRIPTION
[0025] The experimental methods not specifically indicated in the following examples of the application are generally performed according to the conventional conditions, or according to the conditions suggested by the manufacturers. The various common chemical reagents used in the examples are commercially available products.
[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.
[0027] The terms "comprising" and "having," and any variations thereof, as used in the present application are intended to cover a non-exclusive inclusion. For example, a process, method, article, or apparatus that comprises a list of steps or modules is not necessarily limited to those steps or modules which are recited, but can optionally include additional steps or modules not expressly listed or inherent to such process, method, article, or apparatus.
[0028] The "at least one" mentioned in the present application refers to one or more than one. The "and / or" describes the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the three cases of A existing alone, A and B existing together, and B existing alone.
[0029] The specific embodiments are described below.
[0030] Example 1
[0031] The present embodiment provides a phosphate-modified polyether polyol, which is prepared by the following method:
[0032] In a 1L three-necked flask equipped with a thermometer, mechanical stirring and a reflux condenser, 1 mol of polypropylene glycol, 1.3 mol of monobutyl phosphate were sequentially added, and the reaction was stirred at 85°C in an oil bath for 8h. After the reaction was completed, the solvent and low molecular substances were removed by distillation at 100°C under reduced pressure for 4h to obtain phosphate-modified polyether polyol leveling agent 1.
[0033] Example 2
[0034] The present embodiment provides a phosphate-modified polyether polyol, which is prepared by the following method:
[0035] In a 1L three-necked flask equipped with a thermometer, mechanical stirring and a reflux condenser, 1 mol of polypropylene glycol, 1.3 mol of monobutyl phosphate were sequentially added, and the reaction was stirred at 85°C in an oil bath for 8h. After the reaction was completed, the solvent and low molecular substances were removed by distillation at 100°C under reduced pressure for 4h to obtain phosphate-modified polyether polyol leveling agent 1.
[0036] Example 3
[0037] In a 1L three-necked flask equipped with a thermometer, mechanical stirring and a reflux condenser, 1 mol of polypropylene glycol, 1.3 mol of monobutyl phosphate were sequentially added, and the reaction was stirred at 85°C in an oil bath for 8h. After the reaction was completed, the solvent and low molecular substances were removed by distillation at 100°C under reduced pressure for 4h to obtain phosphate-modified polyether polyol leveling agent 1.
[0038] Example 4
[0039] The present embodiment provides a phosphate-modified polyether polyol, which is prepared by the following method:
[0040] In a 1L three-necked flask equipped with a thermometer, mechanical stirring and a reflux condenser, 1 mol of polypropylene glycol, 1.3 mol of monobutyl phosphate were sequentially added, and the reaction was stirred at 85°C in an oil bath for 8h. After the reaction was completed, the solvent and low molecular substances were removed by distillation at 100°C under reduced pressure for 4h to obtain phosphate-modified polyether polyol leveling agent 1.
[0041] Example 5
[0042] The present example provides a phosphate-modified polyether polyol, which is prepared by the following method:
[0043] In a 1L three-necked flask equipped with a thermometer, mechanical stirring and a reflux condenser, 1 mol of polyethylene glycol, 1.4 mol of 2-ethylhexyl phosphate were sequentially added, and the reaction was stirred in an 80°C oil bath for 9 h. After the reaction was completed, the solvent and low molecular weight substances were removed by distillation at 120°C under reduced pressure for 4 h to obtain phosphate-modified polyether polyol leveling agent 5.
[0044] Example 6
[0045] The present example provides a phosphate-modified polyether polyol, which is prepared by the following method:
[0046] In a 1L three-necked flask equipped with a thermometer, mechanical stirring and a reflux condenser, 0.5 mol of polyethylene glycol, 0.5 mol of polypropylene glycol, and 1.5 mol of glycerol phosphate were sequentially added, and the reaction was stirred in a 95°C oil bath for 6 h. After the reaction was completed, the solvent and low molecular weight substances were removed by distillation at 115°C under reduced pressure for 3 h to obtain phosphate-modified polyether polyol leveling agent 6.
[0047] Example 7
[0048] The present example provides an adhesive silver paste for capacitors, the preparation raw materials of which include the phosphate-modified polyorganosiloxane leveling agent 1 prepared in Example 1, and are specifically prepared from the following raw materials in parts by weight: 12 parts of resin, 70 parts of silver powder, 0.2 parts of leveling agent 1, 17.8 parts of solvent, and the surface of the silver powder is treated with oleic acid or stearic acid.
[0049] The adhesive silver paste is prepared by the following method: weighing the raw materials in proportion, uniformly dispersing them by stirring, then grinding them using a three-roll grinder, and finally dispersing and stirring to obtain the adhesive silver paste.
[0050] Examples 8-12
[0051] Examples 8-12 are used to illustrate the adhesive silver paste and the preparation method thereof disclosed in the present application, most of the operations of which are the same as those of Example 7, and the specific operations are shown in Table 1, and the preparation method is the same as that of Example 7.
[0052] Comparative Examples 1-4
[0053] Comparative Examples 1-4 are used to compare the adhesive silver paste and the preparation method thereof disclosed in the present application, most of the operations of which are the same as those of Example 7, and the specific operations are shown in Table 1, and the preparation method is the same as that of Example 7.
[0054] Table 1
[0055]
[0056] Performance test
[0057] The prepared silver adhesive paste was subjected to the following performance tests:
[0058] (1) The viscosity of the silver adhesive paste was tested (viscosity test standard: GB / T2794);
[0059] (2) The flow rate of the silver adhesive paste was tested in a stainless steel groove with an inclination angle of 30 °C;
[0060] (3) Volume resistivity: a volume resistance tester was used to test the volume resistivity of the cured silver adhesive paste film layer (30 um thick);
[0061] (4) A 2V470uf aluminum foil was used to prepare a capacitor single piece, the surface of the capacitor single piece containing the impregnated carbon paste and the impregnated silver was rolled or dotted with the silver adhesive paste, and a five-layer polymer laminated aluminum capacitor was assembled to obtain a chip polymer laminated aluminum capacitor, and the equivalent series resistance ESR of the chip polymer laminated aluminum capacitor was detected.
[0062] Table 2 below is the test result:
[0063] Table 2
[0064]
[0065] As can be seen from the above test results, the silver adhesive paste prepared by using the phosphate ester modified polyether polyol leveling agent of the application has excellent leveling property and high conductivity, and can make the capacitor have low ESR.
[0066] Compared with Example 7, Comparative Examples 1-3 respectively use commercially available polypropylene glycol ether, polyethylene glycol ether, polypropylene glycol ether and polyethylene glycol ether mixture as leveling agent, the flow rate of the prepared silver adhesive paste is lower, the volume resistivity of the cured silver adhesive paste film layer is larger, the ESR of the silver adhesive paste used for preparing the chip polymer laminated aluminum capacitor is obviously increased, and the capacitor performance is decreased.
[0067] Compared with Example 7, Comparative Example 4 directly uses polyglycerol ether and monobutyl phosphate mixture, without condensation reaction, the flow rate of the prepared silver adhesive paste is obviously reduced, the volume resistivity is increased, the capacitor ESR is increased, and the effect of using the phosphate ester modified polyether polyol as the leveling agent cannot be obtained.
[0068] In summary, the phosphate ester modified polyether polyol can be used to prepare a silver adhesive paste for capacitor with excellent leveling property and high conductivity (low ESR), which is very suitable for preparing high-performance MLPC.
[0069] Any combination of the technical features in the above-described embodiments can be made. For the sake of brevity, the description herein has not described all possible combinations of the technical features in the above-described embodiments, however, it is understood that any combination of the technical features is within the scope of the present disclosure as long as the combination does not result in a contradiction.
[0070] The above-described embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the patent scope of the present application. It should be pointed out that, for ordinary skilled persons in the art, several modifications and improvements can be made without departing from the concept of the present application, and these are within the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.
Claims
1. A phosphate-modified polyether polyol characterized in that, at least one of the compounds represented by the following structural formula I: wherein R1, R2 are independently selected from ethyl, propyl, R3, R4 are independently selected from hydrogen, methyl, ethyl, butyl, glyceryl, 2-ethylhexyl, isooctyl, and at least one of R3, R4 is not hydrogen; a, b are integers, and 5≤a≤100, 5≤b≤100.
2. The method for producing a phosphoric acid ester-modified polyether polyol according to claim 1, characterized by, The method comprises the following steps: mixing polyether polyol with phosphate ester uniformly, conducting condensation reaction at 70-100℃, and distilling the reaction product under reduced pressure to obtain the phosphate ester modified polyether polyol.
3. The production method according to claim 2, wherein The condensation reaction time is 4-10h.
4. The production method according to claim 2, wherein The temperature of the distillation under reduced pressure is 90-120℃.
5. The production method according to claim 2, wherein The molar ratio of the polyether polyol to the phosphate ester is (0.8-1.5):(1.0-2.0).
6. Use of the phosphate ester modified polyether polyol of claim 1 or the phosphate ester modified polyether polyol prepared by the method of any one of claims 2-5 in preparing an adhesive silver paste for capacitors.
7. A bonding silver paste for capacitors, characterized in that, The adhesive silver paste is prepared from the following raw materials by weight: 5-15 parts of resin, 60-80 parts of silver powder, 0.1-1.5 parts of the phosphate ester modified polyether polyol of claim 1 or the phosphate ester modified polyether polyol prepared by the method of any one of claims 2-5, and 10-25 parts of solvent.
8. The silver paste for a capacitor as claimed in claim 7, wherein The resin is selected from at least one of acrylic resin, epoxy resin, chlorovinyl resin, polyurethane resin, and polyester resin; and / or, The silver powder is selected from at least one of spherical silver with a particle size of 0.5-10um and flaky silver with a particle size of 1-15um, and the surface of the silver powder is treated with oleic acid or stearic acid.
9. The silver paste for a capacitor as claimed in claim 7, wherein The solvent is selected from two or more of butyl acetate, propylene glycol methyl ether acetate, ethylene glycol butyl ether, ethylene glycol butyl ether acetate, diethylene glycol ethyl ether acetate, and diethylene glycol butyl ether acetate.
10. A capacitor characterized by The raw materials for preparing the capacitor comprise the adhesive silver paste of any one of claims 7-9.