New energy capacitor coating and preparation process thereof

Abstract

The invention discloses a new energy capacitor coating and a preparation method thereof. Comprising the following components: 30 to 35 parts of modified polyester polyol resin, 3 to 5 parts of saturated polyester resin, 6 to 8 parts of blocked isocyanate, 3 to 4 parts of a resin modifier, 0.2 to 0.3 part of an adhesion promoter, 0.08 to 0.12 part of slipping wax, 0.1 to 0.2 part of an organic tin catalyst, 0.3 to 0.5 part of an antifoaming agent, 0.15 to 0.20 part of a leveling agent and 45 to 50 parts of a solvent. Meanwhile, the insulating strength of a paint film reaches AC400V without breakdown, moisture and corrosive media can be effectively isolated, the problems that a traditional paint is insufficient in insulating property, good in mechanical adaptability and excellent in deep drawing resistance are solved, the paint is adaptive to a capacitor shell drawing processing technology, and the problem that the paint film is damaged in the deep processing process is solved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of capacitor protective coating, in particular to a new energy capacitor coating and a manufacturing process thereof. BACKGROUND

[0002] Capacitors are core components in electronic circuits, and especially in the fields of new energy equipment, consumer electronics, industrial control power supply, etc., the reliability of capacitors directly determines the operation stability of the equipment. New energy capacitors such as aluminum electrolytic capacitors, film capacitors and super capacitors usually use aluminum plates and other metal materials as the shell, which are easily affected by factors such as moisture, corrosive media, high temperature and chemical reagents during use. At the same time, the mechanical properties of the coating are also required to be strict during the drawing process of the capacitor shell.

[0003] According to the search, the application disclosed in Chinese patent publication No. CN120399512A relates to a capacitor aluminum alloy shell protective coating and a preparation method thereof, and belongs to the technical field of coating preparation. The modified epoxy resin is prepared by modifying the epoxy resin with two kinds of ultraviolet absorbers. The ultraviolet absorber is chemically bonded with the epoxy resin, is resistant to migration, significantly improves the anti-ultraviolet and anti-aging performance of the coating, delays the degradation of the resin, and cooperates with the silicone-modified FEVE fluororesin to give high weather resistance and chemical stability, further resists environmental erosion, and the antioxidant-modified alkyd resin is chemically bonded to give significant antioxidant performance. Under the interaction of the leveling agent, the defoaming agent and the dispersant, the coating defects can be obviously reduced, which is helpful to prolong the service life of the capacitor shell in outdoor or strong light environment.

[0004] According to the search, the application disclosed in Chinese patent publication No. CN120118582A relates to the processing field of capacitor packaging coating, and specifically discloses a fast-drying packaging coating for film capacitors, a preparation method and application. The fast-drying packaging coating for film capacitors is composed of A component and B component with a mass ratio of 100:90-100. The A component includes 30-50 parts of silicone-modified epoxy resin, 20-30 parts of polyether polyol, 10-25 parts of toughening filler, 1-3 parts of coated tackifier, 1-3 parts of flow improver and 0.5-1 part of defoaming agent. The B component includes 45-75 parts of curing agent, 1-2 parts of accelerator, 1-1.5 parts of antioxidant and 1-2 parts of weathering agent. The preparation method is as follows: the A component and the B component are prepared respectively, packaged respectively, mixed immediately, and the packaging coating is obtained. The application is applied to film capacitors and has the advantages of fast drying, good moisture resistance, good flexibility and high adhesion stability.

[0005] The existing capacitor shell coating has many defects: some coatings have insufficient insulation performance, prone to breakdown, and have safety hazards; some coatings have poor deep drawing performance, and the paint film is prone to cracking during capacitor shell drawing processing; some coatings have poor high temperature resistance and chemical corrosion resistance, and are prone to yellowing and film peeling after long-term use, which cannot meet the high reliability requirements of new energy field capacitors.

[0006] To this end, we propose a new energy capacitor coating and its manufacturing process to solve the above problems. SUMMARY

[0007] The purpose of the present application is to solve the problems existing in the prior art and propose a new energy capacitor coating and its manufacturing process.

[0008] In order to achieve the above purpose, the present application adopts the following technical scheme: A new energy capacitor coating, by weight, comprising the following components: modified polyester polyol resin 30-35 parts, saturated polyester resin 3-5 parts, blocked isocyanate 6-8 parts, resin modifier 3-4 parts, adhesion promoter 0.2-0.3 parts, slip wax 0.08-0.12 parts, organic tin catalyst 0.1-0.2 parts, defoaming agent 0.3-0.5 parts, leveling agent 0.15-0.20 parts, solvent 45-50 parts.

[0009] Further preferably, the modified polyester polyol resin is a linear saturated aliphatic diol or a linear saturated aliphatic triol, and the modified polyester polyol resin has a molecular weight of 1500-3000; the saturated polyester resin is a hydroxyl-terminated linear chain, and the saturated polyester resin has a molecular weight of 20000-35000.

[0010] Further preferably, the blocked isocyanate is one of TDI mixture, IPDI mixture, and HDI mixture, and the deblocking temperature of the blocked isocyanate is 115-249℃.

[0011] Further preferably, the resin modifier is a polyester polyol or a polyurethane diol, the adhesion promoter is an aryl phosphate ester, the slip wax is micronized polyethylene, and the slip wax has a molecular weight of 800-1800.

[0012] Further preferably, the organic tin catalyst is dibutyltin diacetate, the defoaming agent is a polyester-modified polydimethylsiloxane, and the leveling agent is an acrylate.

[0013] Further preferably, the solvent is a mixture of propylene glycol methyl ether acetate and DBE, and the coating has a paint film insulation coefficient ≥ 3.8 x 10 12 Ω·cm after curing.

[0014] The application discloses a preparation process of a new energy capacitor coating, and has the characteristics that in step one, modified polyester polyol resin, saturated polyester resin and blocked isocyanate are added into a dispersion device for dispersion to obtain a premixed material; In step two, resin modifier, adhesion promoter, slip wax, organic tin catalyst, defoaming agent, leveling agent and solvent are sequentially added into the dispersion device for dispersion, and the new energy capacitor coating is obtained after uniform mixing.

[0015] Further preferably, in step 1, the dispersion speed is 1500-1800 rpm, and the dispersion time is 10 minutes.

[0016] Further preferably, the dispersion speed is 800-1200 rpm, and the dispersion time is 30-50 minutes.

[0017] Compared with the prior art, the application has the following beneficial effects: 1. The insulation protection performance is improved, meanwhile, the insulation strength of the paint film reaches AC400V and is not punctured, the moisture and corrosive medium can be effectively isolated, and the insufficient insulation performance of the traditional coating is solved. 2. The mechanical adaptability is good, the coating has excellent deep drawing performance, the coating can adapt to the deep drawing process of the capacitor shell, and the paint film breakage problem in the deep processing process is avoided. 3. The environmental stability is comprehensive and leading, the paint film is not yellow and is not cracked under high temperature, has excellent moisture resistance and aging resistance, has no film peeling phenomenon in long-term use, and the service life of the capacitor is significantly improved. 4. The construction and appearance effect are better, the coating has good leveling property, the paint film after construction is smooth and has no orange peel and bubbles, and the high-precision assembly requirement of the new energy capacitor shell is met. Specific embodiments

[0018] The technical solutions in the embodiments of the application will be clearly and completely described below, obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments.

[0019] The modified polyester polyol resin is linear saturated aliphatic diol and triol, has a molecular weight of 1500-3000, is used as a main film-forming material, provides good flexibility and basic film-forming performance for the coating, and the saturated polyester resin is a hydroxyl-terminated straight-chain type, has a molecular weight of 20000-35000, and can enhance the mechanical performance and chemical corrosion resistance of the paint film. The blocked isocyanate is one of a TDI, IPDI and HDI mixture, has a deblocking temperature of 115-249 DEG C, is used as a cross-linking curing agent, can react with the polyester resin to improve the high-temperature resistance and adhesion of the paint film, the resin modifier is polyester polyol and polyurethane diol, can adjust the cross-linking degree and paint film flexibility of the coating, and optimizes the comprehensive performance of the coating. The adhesion promoter is aryl phosphate, which can significantly enhance the adhesion of the paint film to the aluminum plate substrate, ensure that the grid test reaches 0 level, and the slip wax is micronized polyethylene with a molecular weight of 800-1800, which can improve the slip and scratch resistance of the paint film and reduce the scratches during the drawing process of the capacitor shell. The organic tin catalyst is dibutyl tin diacetate, which can accelerate the deblocking and crosslinking reaction process of the blocked isocyanate, improve the curing efficiency, and the defoaming agent is polyester modified polydimethylsiloxane, which can effectively eliminate the bubbles generated during the preparation and application of the coating, and ensure the smooth appearance of the paint film without bubbles. The leveling agent is acrylate, which can improve the leveling performance of the coating to avoid orange peel phenomenon, and the solvent is a mixture of propylene glycol methyl ether acetate and DBE, which can effectively dissolve each component, adjust the viscosity of the coating, and facilitate construction and film formation. The insulation coefficient of the paint film after curing is ≥3.8×10¹²Ω·cm, which is significantly better than traditional coatings in terms of insulation protection performance. The manufacturing process of the new energy capacitor coating includes the following steps: Step one: add modified polyester polyol resin, saturated polyester resin and blocked isocyanate to the dispersion equipment, disperse at a speed of 1500-1800 rpm for 10 minutes, so that the resin and crosslinking curing agent are fully pre-mixed, laying a foundation for subsequent crosslinking reaction; Step two: add resin modifier, adhesion promoter, slip wax, organic tin catalyst, defoaming agent, leveling agent and solvent to the pre-mixed material in turn, disperse at a speed of 800-1200 rpm for 30-50 minutes, and mix uniformly to obtain the new energy capacitor coating. This step-by-step dispersion process can avoid uneven mixing of each component and ensure stable performance of the coating. Example

[0020] A new energy capacitor coating, by weight, includes: modified polyester polyol resin 30 parts, saturated polyester resin 3 parts, blocked isocyanate 6 parts, resin modifier 3 parts, adhesion promoter 0.2 parts, slip wax 0.08 parts, organic tin catalyst 0.1 parts, defoaming agent 0.3 parts, leveling agent 0.15 parts, solvent 45 parts. Its manufacturing process is: Step one: add 30 parts of modified polyester polyol resin, 3 parts of saturated polyester resin and 6 parts of blocked isocyanate to a high-speed disperser, disperse at a speed of 1500 rpm for 10 minutes to obtain a pre-mixed material; Step two: add 3 parts of resin modifier, 0.2 parts of adhesion promoter, 0.08 parts of slip wax, 0.1 parts of organic tin catalyst, 0.3 parts of defoaming agent, 0.15 parts of leveling agent and 45 parts of solvent to the pre-mixed material in turn, disperse at a speed of 800 rpm for 50 minutes, and mix uniformly to obtain the new energy capacitor coating.

[0021] The coating is baked at 170°C for 25 minutes to cure, and the performance is tested: insulation strength AC400V is not punctured, insulation coefficient is 3.8*10^12 Ω·cm, chloride ion content is 0.8PPM, conductivity is 2.2 μS / cm, cup test indentation is 5mm without cracking, no yellowing and no cracking at high temperature of 280°C, no film peeling after 13pH alkali boiling at 100°C for 30 minutes, grid test adhesion is 0 level, and the paint film is smooth without orange peel and bubbles. Embodiment

[0022] A new energy capacitor coating, by weight, comprises: modified polyester polyol resin 32 parts, saturated polyester resin 4 parts, blocked isocyanate 7 parts, resin modifier 3.5 parts, adhesion promoter 0.25 parts, slip wax 0.1 parts, organic tin catalyst 0.15 parts, defoaming agent 0.4 parts, leveling agent 0.18 parts, solvent 48 parts. The manufacturing process is: Step one: add 32 parts of modified polyester polyol resin, 4 parts of saturated polyester resin and 7 parts of blocked isocyanate into a high-speed dispersing machine, and disperse at a speed of 1650 rpm for 10 minutes to obtain a premixed material; Step two: add 3.5 parts of resin modifier, 0.25 parts of adhesion promoter, 0.1 parts of slip wax, 0.15 parts of organic tin catalyst, 0.4 parts of defoaming agent, 0.18 parts of leveling agent and 48 parts of solvent into the premixed material in sequence, and disperse at a speed of 1000 rpm for 40 minutes. After uniform mixing, the new energy capacitor coating is obtained. The coating is baked at 170°C for 25 minutes to cure, and the performance is tested: insulation strength AC400V is not punctured, insulation coefficient is 4.2*10^12 Ω·cm, chloride ion content is 0.6PPM, conductivity is 1.8 μS / cm, cup test indentation is 5mm without cracking, no yellowing and no cracking at high temperature of 280°C, no film peeling after 13pH alkali boiling at 100°C for 30 minutes, grid test adhesion is 0 level, and the paint film is smooth without orange peel and bubbles. Embodiment

[0023] A new energy capacitor coating, by weight, comprises: modified polyester polyol resin 32 parts, saturated polyester resin 4 parts, blocked isocyanate 7 parts, resin modifier 3.5 parts, adhesion promoter 0.25 parts, slip wax 0.1 parts, organic tin catalyst 0.15 parts, defoaming agent 0.4 parts, leveling agent 0.18 parts, solvent 48 parts. The manufacturing process is: Step one: add 32 parts of modified polyester polyol resin, 4 parts of saturated polyester resin and 7 parts of blocked isocyanate into a high-speed dispersing machine, and disperse at a speed of 1650 rpm for 10 minutes to obtain a premixed material; Step two: add 4 parts of resin modifier, 0.3 parts of adhesion promoter, 0.12 parts of slip wax, 0.2 parts of organic tin catalyst, 0.5 parts of defoamer, 0.20 parts of leveling agent and 50 parts of solvent into the premixed material, disperse at 1200 rpm for 30 minutes, mix uniformly, and then the new energy capacitor paint is obtained.

[0024] The paint is baked at 170°C for 25 minutes to cure, and the performance is tested: insulation strength AC400V no breakdown, insulation coefficient 4.5x10^12 Ω·cm, chloride ion content 0.5PPM, conductivity 1.5μS / cm, cup test indentation 5mm no cracking, no yellowing and no cracking at 280°C high temperature, no film peeling after 13pH alkali boiling at 100°C for 30 minutes, grid test adhesion 0 level, smooth film without orange peel and bubbles. II. Comparative Example Comparative Example 1 The paint is mixed by weight parts, the main components are ordinary polyester resin 25 parts, toluene diisocyanate 5 parts, talc 10 parts, calcium carbonate 5 parts, xylene solvent 50 parts, no resin modifier, slip wax and special adhesion promoter. Disperse and mix according to the conventional process, bake at 160°C for 30 minutes to cure, test performance: insulation strength AC300V breakdown, insulation coefficient 4.2x10^11 Ω·cm, chloride ion content 3.5PPM, conductivity 5.8μS / cm, cup test indentation 3mm cracking, yellowing obvious at 200°C high temperature, partial film peeling after 13pH alkali boiling at 100°C for 30 minutes, grid test adhesion 2 level, film with slight orange peel. Comparative Example 2 The paint is mixed by weight parts, the main components are ordinary polyester polyol resin 30 parts, blocked TDI isocyanate 6 parts, kaolin 8 parts, zinc stearate 0.5 parts, dibutyltin dilaurate 0.2 parts, mineral oil defoamer 0.3 parts, solvent (xylene + ethyl acetate) 55 parts. Disperse at 1200 rpm for 40 minutes, bake at 170°C for 25 minutes to cure, test performance: insulation strength AC350V breakdown, insulation coefficient 8.5x10^11 Ω·cm, chloride ion content 2.8PPM, conductivity 4.6μS / cm, cup test indentation 4mm cracking, cracking at 250°C high temperature, film peeling area up to 30% after 13pH alkali boiling at 100°C for 30 minutes, grid test adhesion 1 level, film with a small amount of bubbles. Comparative Example 3 The paint is mixed by weight parts, the main components are epoxy resin 28 parts, polyamide curing agent 8 parts, silica filler 6 parts, solvent (cyclohexanone + butanol) 58 parts. Dispersed at 1200 rpm for 40 minutes, baked at 170 ℃ for 25 minutes to cure, test performance: insulation strength AC400V not breakdown, insulation coefficient 1.2*10^12 Ω*cm, chloride content 1.5 PPM, conductivity 3.2 μS / cm, cup test indentation 2 mm cracking (brittleness), no yellowing at high temperature of 280 ℃ but slight cracking, 13 pH alkali boiling 100 ℃ for 30 minutes without stripping, cross-cut test adhesion 1 level, poor paint film leveling.

[0025] In addition, when the terms "first", "second", "third" and the like are used in the specification of the present application to describe various features, these terms are only used to distinguish the features, and cannot be understood as indicating or implying the relevance, relative importance between the features, or implicitly indicating the number of the indicated features.

Claims

1. A new energy capacitor coating, characterized in that, By weight parts, including the following components: modified polyester polyol resin 30-35 parts, saturated polyester resin 3-5 parts, blocked isocyanate 6-8 parts, resin modifier 3-4 parts, adhesion promoter 0.2-0.3 parts, slip wax 0.08-0.12 parts, organic tin catalyst 0.1-0.2 parts, defoamer 0.3-0.5 parts, leveling agent 0.15-0.20 parts, solvent 45-50 parts.

2. The new energy capacitor coating according to claim 1, characterized in that, The modified polyester polyol resin is linear saturated aliphatic diol or linear saturated aliphatic triol, the molecular weight of the modified polyester polyol resin is 1500-3000; the saturated polyester resin is hydroxyl-terminated linear, the molecular weight of the saturated polyester resin is 20000-35000.

3. The new energy capacitor coating according to claim 1, characterized in that, The blocked isocyanate is one of TDI mixture, IPDI mixture, HDI mixture, and the deblocking temperature of the blocked isocyanate is 115-249℃.

4. The new energy capacitor coating of claim 1, wherein, The resin modifier is polyester polyol or polyurethane diol, the adhesion promoter is aryl phosphate, the slip wax is micronized polyethylene, and the molecular weight of the slip wax is 800-1800.

5. The new energy capacitor coating of claim 1, wherein, The organic tin catalyst is dibutyltin diacetate, the defoamer is polyester modified polydimethylsiloxane, and the leveling agent is acrylate.

6. The new energy capacitor coating of claim 1, wherein, The solvent is a mixture of propylene glycol methyl ether acetate and DBE, and the insulation coefficient of the paint film after curing is ≥3.8×10¹²Ω·cm.

7. The process for producing a new energy capacitor coating according to claims 1-6, characterized in that, Step one: add the modified polyester polyol resin, saturated polyester resin and blocked isocyanate into the dispersion equipment for dispersion to obtain a premix material; Step two: add the resin modifier, adhesion promoter, slip wax, organic tin catalyst, defoamer, leveling agent and solvent into the premix material in sequence and disperse in the dispersion equipment, and then mix uniformly to obtain the new energy capacitor coating.

8. The process for making a new energy capacitor coating according to claim 7, wherein In step 1, the dispersion speed is 1500-1800 rpm, and the dispersion time is 10 minutes.

9. The process for making a new energy capacitor coating according to claim 7, wherein In step 2, the dispersion speed is 800-1200 rpm, and the dispersion time is 30-50 minutes.