阅读说明：本技术 一种高耐压低阻抗铝电解电容器纸及其制备方法 (High-voltage-resistance low-impedance aluminum electrolytic capacitor paper and preparation method thereof ) 是由 宋欢 杨清 胡健 唐莹 陈磊 王贤炉 王泽嘉 佘攀 于 2020-06-18 设计创作，主要内容包括：本发明公开了一种高耐压低阻抗铝电解电容器纸,主要由第一紧度层和第二紧度层复合后烘干而成,所述第一紧度层的原料包括以下重量份的各组分：绝缘木浆纤维60-98份,天丝纤维2-40份；所述第二紧度层的原料包括以下重量份的各组分：绝缘木浆纤维40-98份,粘胶纤维2-60份。得到的产品纤维分散均匀,成型匀度好,耐压特性好,且具有低的ESR值,吸液效果好,具有广阔的应用前景。本发明还公开了其制备方法,操作简单,制作成本低廉,通过严格控制第一紧度层和第二紧度层的打浆度,保证了纸张的耐压特性,第一紧度层和第二紧度层进行湿复合、烘干、卷曲、分切后制得,制备得到的电容器纸能够满足高端铝电解电容器制造的性能需求。(The invention discloses high-voltage-resistance low-impedance aluminum electrolytic capacitor paper which is mainly formed by compounding and drying a first tightness layer and a second tightness layer, wherein the raw material of the first tightness layer comprises the following components in parts by weight: 60-98 parts of insulating wood pulp fiber and 2-40 parts of tencel fiber; the raw materials of the second tightness layer comprise the following components in parts by weight: 40-98 parts of insulating wood pulp fiber and 2-60 parts of viscose fiber. The obtained product has the advantages of uniform fiber dispersion, good molding uniformity, good pressure resistance, low ESR value, good liquid absorption effect and wide application prospect. The invention also discloses a preparation method of the capacitor paper, which is simple to operate and low in manufacturing cost, the pressure resistance characteristic of the paper is ensured by strictly controlling the beating degree of the first tightness layer and the second tightness layer, and the capacitor paper prepared by the first tightness layer and the second tightness layer is prepared by wet compounding, drying, curling and cutting, and can meet the performance requirement of high-end aluminum electrolytic capacitor manufacturing.)

1. The high-voltage-resistance low-impedance aluminum electrolytic capacitor paper is characterized by being mainly formed by compounding a first tightness layer and a second tightness layer, wherein the raw materials of the first tightness layer comprise the following components in parts by weight: 60-98 parts of insulating wood pulp fiber and 2-40 parts of tencel fiber; the raw materials of the second tightness layer comprise the following components in parts by weight: 40-98 parts of insulating wood pulp fiber and 2-60 parts of viscose fiber.

2. The high-voltage-resistance low-impedance aluminum electrolytic capacitor paper as recited in claim 1, wherein the raw material of the first tension layer comprises the following components in parts by weight: 75-90 parts of insulating wood pulp fiber and 10-25 parts of tencel fiber; the raw materials of the second tightness layer comprise the following components in parts by weight: 75-90 parts of insulating wood pulp fiber and 10-25 parts of viscose fiber.

3. The high voltage-resistant low impedance aluminum electrolytic capacitor paper as claimed in claim 1, wherein the viscose fiber has a fineness of 0.2-1.5 denier and a length of 2-10 mm.

4. The aluminum electrolytic capacitor paper with high voltage resistance and low impedance as claimed in claim 1, wherein the surface of the second tension layer is coated with a polyvinyl alcohol glue layer, and the coating amount is 0.1-2g/m²。

5. The high-voltage-resistance low-impedance aluminum electrolytic capacitor paper as recited in claim 1, wherein the mass ratio of the first tension layer to the second tension layer is 0.3 to 3.0.

6. The high voltage-resistant low impedance aluminum electrolytic capacitor paper as claimed in any one of claims 1 to 5, wherein the first tightness layer is obtained by mixing and then pulping the insulating wood pulp fibers and tencel fibers, and controlling the beating degree of the mixed pulp to be more than 90 ° SR; and the second tightness layer is obtained by grinding the insulating wood pulp fiber into pulp, controlling the beating degree of the pulp to be 15-60 DEG SR, and mixing the obtained insulating wood pulp with the viscose fiber.

7. The high-voltage-resistance low-impedance aluminum electrolytic capacitor paper as claimed in claim 6, wherein the first tightness layer is obtained by mixing and then pulping insulating wood pulp fibers and tencel fibers, and controlling the pulping degree of the mixed pulp to be more than 94 ° SR; and the second tightness layer is obtained by pulping the insulating wood pulp fibers, controlling the beating degree of the second tightness layer to be 25-50 DEG SR and mixing the second tightness layer with the viscose fibers.

8. A method for preparing the high withstand voltage low impedance aluminum electrolytic capacitor paper as claimed in any one of claims 1 to 7, comprising the steps of:

(1) uniformly mixing the insulating wood pulp fibers and the tencel fibers, and then grinding the mixture into thick liquid, wherein the beating degree of the thick liquid is controlled to be more than 90 DEG SR after grinding into thick liquid, so as to prepare a first tightness layer;

(2) pulping the insulating wood pulp fiber, controlling the pulping degree to be 15-60 DEG SR after pulping, and then uniformly mixing the insulating wood pulp fiber with the viscose fiber to prepare a second tightness layer;

(3) and (3) carrying out wet compounding on the first tightness layer obtained in the step (1) and the second tightness layer obtained in the step (2), drying, curling and slitting to obtain the high-voltage-resistance low-impedance aluminum electrolytic capacitor paper.

9. The method of claim 8, wherein the first loft layer is formed using a fourdrinier forming process and the second loft layer is formed using a slant wire forming process; in the step (2), the pulping concentration of the insulating wood pulp fiber is controlled to be 0.5-3.5% when pulping.

10. The method according to claim 8 or 9, wherein in the step (3), after the first tension layer and the second tension layer are wet-compounded, a layer of polyvinyl alcohol glue is sprayed on the second tension layer.

Technical Field

The invention belongs to the technical field of capacitor paper, and particularly relates to high-voltage-resistance low-impedance aluminum electrolytic capacitor paper and a preparation method thereof.

Background

The development trend of the aluminum electrolytic capacitor is mainly towards the characteristics of high voltage resistance, low ESR and the like, and the electrolytic capacitor paper is required to be developed towards the technical directions of high voltage resistance, high liquid absorption, low ESR and the like.

Chinese patent CN201510479886.7 discloses an electrolytic capacitor paper with a multilayer structure and a method for preparing the electrolytic capacitor paper. The paper pulp of the pressure-resistant layer of the electrolytic capacitor paper is selected from sisal, the beating degree of the paper pulp used by the pressure-resistant layer paper is 32-38 DEG SR, the absorption layer paper is of one-layer or multi-layer structure, the paper pulp of the absorption layer paper is selected from one or a mixture of hemp fibers, bast fibers and grass fibers, and the beating degree of the paper pulp used by the absorption layer paper is 15-45 DEG SR. Sisal pulp, bast fibres and straw pulp are expensive and as the first tightness layer, sisal with low freeness does not reach the ideal pressure rating.

The pressure-resistant aluminum electrolytic capacitor paper provided by the Chinese patent CN201811448628.2 has a pressure-resistant layer which is formed by adding nano-cellulose after pulping by using insulating wood pulp fibers, and a liquid absorption layer which is also formed by mixing hemp pulp, cotton pulp and Spanish grass. The pressure-resistant layer is formed by adding the nano-fibers after wood pulp is pulped, the risk of uneven dispersion exists, the price of pulp used for the second tightness layer is high, and the forming is difficult.

Therefore, the development of a novel aluminum electrolytic capacitor paper with low cost, good molding uniformity, high pressure resistance, good liquid absorption and low ESR (equivalent series resistance) is of great significance to the field.

Disclosure of Invention

The technical problem to be solved by the invention is to overcome the defects and defects mentioned in the background technology, and provide aluminum electrolytic capacitor paper with low cost, good molding evenness, high pressure resistance, good liquid absorption and low ESR and a preparation method thereof.

In order to solve the technical problems, the technical scheme provided by the invention is as follows:

the utility model provides a high withstand voltage low impedance aluminum electrolytic capacitor paper, mainly by first tautness layer (high tautness layer) and second tautness layer (low tautness layer) complex form, the raw materials on first tautness layer include each component of following parts by weight: 60-98 parts of insulating wood pulp fiber and 2-40 parts of tencel fiber; the raw materials of the second tightness layer comprise the following components in parts by weight: 40-98 parts of insulating wood pulp fiber and 2-60 parts of viscose fiber.

Preferably, the raw material of the first tension layer comprises the following components in parts by weight: 75-90 parts of insulating wood pulp fiber and 10-25 parts of tencel fiber; the raw materials of the second tightness layer comprise the following components in parts by weight: 75-90 parts of insulating wood pulp fiber and 10-25 parts of viscose fiber.

Preferably, the fineness of the viscose fiber is 0.2-1.5 deniers, and the length of the viscose fiber is 2-10 mm. The size of the viscose fiber is too large, so that the surface of the paper is not flat, and the viscose fiber with the small size is not used in the market and is smaller and more expensive.

Preferably, the surface of the second tightness layer is coated with a polyvinyl alcohol glue layer, and the coating amount is 0.1-2g/m². The more the surface is sprayed with the polyvinyl alcohol glue, the higher the breakdown strength and tensile strength of the paper, but the ESR value of the paper is increased, so the ESR value cannot exceed 2g/m²。

Preferably, the mass ratio of the first tightness layer to the second tightness layer is 0.3-3.0, and more preferably 0.7-2.0.

Preferably, the first tightness layer is obtained by mixing and then pulping the insulating wood pulp fibers and the tencel fibers and controlling the beating degree of the mixed pulp to be more than 90 DEG SR; and the second tightness layer is obtained by grinding the insulating wood pulp fiber into pulp, controlling the beating degree of the insulating wood pulp at 15-60 DEG SR, and mixing the obtained insulating wood pulp with the viscose fiber.

More preferably, the first tightness layer is obtained by mixing and then pulping the insulating wood pulp fibers and the tencel fibers, and controlling the beating degree of the mixed pulp to be more than 94 DEG SR, wherein the beating degree of the mixed pulp has great influence on the performance of the final paper, the beating degree is too low, and the pressure resistance of the paper is poor; the second tightness layer is formed by grinding insulating wood pulp fibers into pulp, the beating degree of the second tightness layer is controlled to be 25-50 degrees SR, and the second tightness layer is obtained by mixing the second tightness layer with viscose fibers.

The first tightness layer (high tightness layer) mainly provides a withstand voltage characteristic due to compact structure, and the second tightness layer (low tightness layer) mainly provides a low impedance characteristic due to loose structure and good electrolyte absorption performance. Insulating wood pulp in the first degree of tightness layer (high degree of tightness layer) grinds thick liquid degree height (control its beating degree and more than 90 SR), provides compact structure, and the tencel fibre of adding is brooming effectual because of dividing the silk, grinds tiny long fiber through grinding the thick liquid back, adds the impedance effect that first degree of tightness layer (high degree of tightness layer) can reduce first degree of tightness layer, and first degree of tightness layer takes the form of the defibrination again after tencel fibre and insulating wood pulp mix, can improve tencel fibrous dispersibility greatly. And the insulating wood pulp degree of itself of the tight degree layer of second (low tight degree layer) is not high, and the structure is comparatively loose, and viscose fiber can not grind the thick liquid, and viscose fiber's addition makes the tight degree layer loose structure of second more loose, and the imbibition ability reinforcing provides the low impedance characteristic. Only by strictly controlling the weight parts and the beating degree of each raw material, the performance of the finally obtained paper is optimal.

The design principle of the beating degree is as follows: the high pressure resistance characteristic is needed, the paper structure is required to be compact, so that the high beating degree of the fiber is required to ensure the compactness of the paper structure, and on the contrary, the low impedance characteristic is required, the paper structure is required to be loose, and the liquid absorption capacity is high. Through a large number of tests, the degree of beating of the first tension layer is more than 90 DEG SR (more preferably more than 94 DEG SR), the degree of beating of the second tension layer is 15-60 DEG SR (more preferably 25-50 DEG SR), and the high voltage resistance characteristic and the low impedance characteristic of the first tension layer (high tension layer) and the second tension layer (low tension layer) can be perfectly balanced.

Based on a general inventive concept, the invention also provides a preparation method of the high-voltage-resistance low-impedance aluminum electrolytic capacitor paper, which comprises the following steps:

(1) uniformly mixing the insulating wood pulp fibers and the tencel fibers, and then grinding the mixture into thick liquid, wherein the beating degree of the thick liquid is controlled to be more than 90 DEG SR after grinding into thick liquid, so as to prepare a first tightness layer;

(2) pulping the insulating wood pulp fiber, controlling the pulping degree to be 15-60 DEG SR after pulping, and then uniformly mixing the insulating wood pulp fiber with the viscose fiber to prepare a second tightness layer;

(3) and (3) carrying out wet compounding on the first tightness layer obtained in the step (1) and the second tightness layer obtained in the step (2), drying, curling and slitting to obtain the high-voltage-resistance low-impedance aluminum electrolytic capacitor paper.

In the above preparation method, preferably, the first tightness layer is prepared by a fourdrinier forming method, and the second tightness layer is prepared by an inclined wire forming method. Generally, the fourdrinier wire forming dewatering area is long and suitable for high-beating-degree forming, the fourdrinier wire forming is adopted for the first tightness layer of the inclined wire dewatering area, the inclined wire dewatering area is short and only suitable for low-beating-degree forming, and the inclined wire forming is adopted for the second tightness layer of the inclined wire dewatering area.

Preferably, in the step (2), the pulping concentration of the insulating wood pulp fiber is controlled to be 0.5-3.5% (mass concentration) when the insulating wood pulp fiber is refined. Under the condition of the pulping concentration, the cutting effect of the insulating wood pulp fiber can be increased under the condition that the pulping degree is 15-60 degrees SR, and the dispersibility of the insulating wood pulp fiber is further improved.

Preferably, in the step (3), after the first tightness layer and the second tightness layer are subjected to wet compounding, a layer of polyvinyl alcohol glue solution is sprayed on the second tightness layer, so that the liquid absorption performance of the second tightness layer can be maintained, and the surface strength and the tensile strength of the second tightness layer can be improved.

Compared with the prior art, the invention has the beneficial effects that:

1. according to the high-voltage-resistance low-impedance aluminum electrolytic capacitor paper, the first tightness layer is made of the mixed pulp of the insulating wood pulp and the tencel fibers, the second tightness layer is made of the mixed pulp of the insulating wood pulp and the viscose, the raw material cost is low, the obtained product is uniform in fiber dispersion, good in forming uniformity and voltage resistance, low in ESR value and good in liquid absorption effect, and the high-voltage-resistance low-impedance aluminum electrolytic capacitor paper has a wide application prospect.

2. The pressure resistance of the first tightness layer is obviously improved by the tencel fiber added in the invention, the good liquid absorption performance of the second tightness layer sprayed with the polyvinyl alcohol glue solution is maintained, the surface strength is greatly improved, and the tensile strength of the paper is improved.

3. The preparation method provided by the invention is simple to operate and low in manufacturing cost, the withstand voltage characteristic of the paper is ensured by strictly controlling the beating degree of the first tightness layer and the second tightness layer, and the prepared capacitor paper can meet the performance requirements of high-end aluminum electrolytic capacitor manufacturing.

Detailed Description

In order to facilitate an understanding of the present invention, the present invention will be described more fully and in detail with reference to the preferred embodiments, but the scope of the present invention is not limited to the specific embodiments below.

Unless otherwise defined, all terms of art used hereinafter have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the present invention.

Unless otherwise specifically stated, various raw materials, reagents, instruments, equipment and the like used in the present invention are commercially available or can be prepared by existing methods.