阅读说明：本技术 一种活性云母纸及其相关制品的制备方法 (Preparation method of active mica paper and related products thereof ) 是由 李俊 李新辉 朱淼 潘斌海 于 2021-02-04 设计创作，主要内容包括：本发明提供了一种活性云母纸及其相关制品的制备方法,包括以下步骤：(1)将经过破碎的云母精浆悬浮液抽到反应釜中并进行稀释；(2)搅拌,加热升温云母悬浮液,并调节云母悬浮液的PH值；(3)向步骤(2)中悬浮液滴加硅烷偶联剂醇溶液；(4)滴加完毕后继续搅拌,降温、过滤、洗涤至中性；(5)向步骤(4)中云母加水稀释到合适浓度后,进行造纸得活性云母纸。本发明制备的云母纸具备硅烷偶联剂上与有机材料发生化学反应的反应基团,极大的增加了云母表面的极性和反应性,增强了分子间的作用力,在制品施胶过程中,能快速与胶黏剂浸润、相容、反应,提高了制品机械强度。(The invention provides a preparation method of active mica paper and related products thereof, which comprises the following steps: (1) pumping the crushed mica seminal plasma suspension into a reaction kettle and diluting; (2) stirring, heating the mica suspension, and adjusting the pH value of the mica suspension; (3) dropwise adding a silane coupling agent alcoholic solution into the suspension in the step (2); (4) after the dropwise addition is finished, stirring, cooling, filtering and washing to be neutral; (5) and (4) adding water into the mica in the step (4) to dilute the mica to a proper concentration, and making paper to obtain the active mica paper. The mica paper prepared by the invention has a reactive group which is chemically reacted with an organic material on a silane coupling agent, so that the polarity and reactivity of the mica surface are greatly increased, the intermolecular acting force is enhanced, the mica paper can be quickly infiltrated, compatible and reacted with an adhesive in the process of gluing a product, and the mechanical strength of the product is improved.)

1. A method for preparing active mica paper and related products is characterized in that: the method comprises the following steps:

(1) pumping the crushed mica fine slurry into a reaction kettle, and diluting to form a suspension;

(2) stirring, heating the mica seminal plasma suspension to a certain temperature, and adjusting the pH value of the mica seminal plasma suspension;

(3) dropwise adding a silane coupling agent alcoholic solution into the mica seminal plasma suspension in the step (2), and controlling the pH value to be stable;

(4) after the dropwise addition is finished, continuously stirring, cooling, filtering and washing to be neutral;

(5) adding water into the mica washed in the step (4) to dilute to a proper concentration, and making paper to obtain active mica paper;

(6) the active mica paper obtained in the step (5) is prepared into a mica plate through sizing, drying, weighting, pressing and cutting;

(7) and (5) compounding the activated mica paper obtained in the step (5) with a reinforcing material through gluing, drying and slitting to prepare the mica tape.

2. The method for preparing the activated mica paper and the related products thereof according to claim 1, wherein the diluted mica content in the reaction kettle in the step (1) is 5% to 30% (w/w), preferably 8% to 25% (w/w), and particularly preferably 12% to 20% (w/w).

3. The method of making the activated mica paper and related articles of claim 1, wherein: the silane coupling agent adopted in the step (3) is hexyltrimethoxysilane, decyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styrenetrimethoxysilane, 3-isobutylpropyltrimethoxysilane, 3-isobutylpropyltriethoxysilane, 3-propenylpropyltrimethoxysilane, N-2 (aminoethyl) 3-aminopropylmethyldimethoxysilane, N-2 (aminoethyl) 3-aminopropyltrimethoxysilane, N-2 (aminoethyl) 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, dodecyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-ureidopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane and the like, preferably 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, N-2 (aminoethyl) 3-aminopropylmethyldimethoxysilane, N-2 (aminoethyl) 3-aminopropyltrimethoxysilane, N-2 (aminoethyl) 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane and 3-aminopropyltriethoxysilane, and particularly preferably 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, and the like, 3-aminopropyl triethoxysilane or their combination.

4. The method of making the activated mica paper and related articles of claim 1, wherein: in the alcoholic solution of the silane coupling agent, the weight ratio of the silane coupling agent to the alcoholic solution is 1 (0.2-20), preferably 1: (0.5-10), particularly preferably 1: (1-4); wherein the alcohol is preferably one or more of methanol, ethanol, n-propanol, isopropanol and n-butanol, and particularly preferably ethanol or isopropanol or the combination of the two.

5. The method of making the activated mica paper and related articles of claim 1, wherein: the silane coupling agent is used in an amount of 0.1% to 10%, preferably 0.5% to 5%, particularly preferably 1% to 3% by dry weight of the mica.

6. The method of making the activated mica paper and related articles of claim 1, wherein: the mica fine pulp is one or more of muscovite fine pulp, phlogopite fine pulp, calcined muscovite fine pulp, calcined phlogopite fine pulp and synthetic mica fine pulp, and the particle size of the mica fine pulp is distributed between-4 meshes and +120 meshes, preferably between-8 meshes and +100 meshes, and more preferably between-10 meshes and 80 meshes.

7. The method of making the activated mica paper and related articles of claim 1, wherein: the temperature in step (2) is from 40 ℃ to 90 ℃, preferably from 65 ℃ to 85 ℃, particularly preferably from 70 ℃ to 80 ℃, and the pH value is from 2 to 10, preferably from 3 to 8, particularly preferably from 4 to 8.

8. The method of making the activated mica paper and related articles of claim 1, wherein: the active mica paper of the step (5) has a reactive group which is chemically combined with the organic material on the silane coupling agent.

9. The method of making the activated mica paper and related articles of claim 1, wherein: the adhesive used for sizing is one of aqueous/oily organic silicon adhesive, polyester adhesive, epoxy resin adhesive, polyurethane adhesive and modified adhesive thereof, and preferably organic silicon adhesive.

10. The method of making the activated mica paper and related articles of claim 1, wherein: the reinforcing material is one or a combination of a plurality of glass fiber cloth, non-woven fabric, polyester film and polyolefin film.

Technical Field

The invention belongs to the technical field of mica products, and particularly relates to active mica paper and a preparation method of related products thereof.

Background

The mica paper is a mica product which is made by using crushed mica or mica powder with a certain particle size distribution as a raw material and using the processes of pulping, papermaking, forming, squeezing and the like to replace natural mica sheets as an electric insulating material and is formed by bonding weak van der Waals force among mica flakes. The mica paper can be used for manufacturing mica plates and mica tapes and is used for electric insulating materials. When manufacturing mica plates and mica tapes, organic adhesives are contacted and soaked with mica paper, and then the adhesives react and solidify in a drying tunnel. The mechanical performance of the mica product is determined by the infiltration and permeability of the adhesive to the mica paper.

At present, because mica paper has extremely poor toughness, in order to enable organic adhesives to fully infiltrate inorganic mica paper, the solid content of the adhesives diluted by a solvent is generally increased, particularly high-grade organic silicon adhesives are adopted to increase the toughness of mica products, but the mica paper which is tightly arranged, has poor air permeability and good insulating property is difficult to effectively utilize.

Patent and literature reports that mica paper containing a coupling agent is prepared by adding the coupling agent into mica pulp, the coupling agent and water cannot be completely dissolved, and the mica paper can be quickly hydrolyzed after being dissolved, so that the coupling agent is unevenly distributed and is not firmly bonded in the papermaking process and is easily washed off by water; in the process of sizing mica plates and mica tapes, the coupling agent is added into the adhesive, so that the problems of slow hydrolysis (no water), preferential combination with glass fibers (large specific surface area) and the like of the coupling agent exist, and the increase of the coupling strength of the mica paper is limited.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a preparation method of active mica paper and related products thereof.

The invention is realized by the following steps:

the invention provides a preparation method of active mica paper and related products thereof, which is characterized in that: the method comprises the following steps:

(1) pumping the crushed mica fine slurry into a reaction kettle, and diluting to form a suspension;

(2) stirring, heating the mica seminal plasma suspension to a certain temperature, and adjusting the pH value of the mica seminal plasma suspension;

(3) dropwise adding a silane coupling agent alcoholic solution into the mica seminal plasma suspension in the step (2), and controlling the pH value to be stable;

(4) after the dropwise addition is finished, continuously stirring, cooling, filtering and washing to be neutral;

(5) adding water into the mica washed in the step (4) to dilute to a proper concentration, and making paper to obtain active mica paper;

(6) the active mica paper obtained in the step (5) is prepared into a mica plate through sizing, drying, weighting, pressing and cutting;

(7) and (5) compounding the activated mica paper obtained in the step (5) with a reinforcing material through gluing, drying and slitting to prepare the mica tape.

Further, the diluted mica content in the reaction kettle in the step (1) is 5-30% (w/w), preferably 8-25% (w/w), and particularly preferably 12-20% (w/w).

Further, the silane coupling agent used in the step (3) is hexyltrimethoxysilane, decyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styrenetrimethoxysilane, 3-isobutylpropyltrimethoxysilane, 3-isobutylpropyltriethoxysilane, 3-propenylpropyltrimethoxysilane, N-2 (aminoethyl) 3-aminopropylmethyldimethoxysilane, N-2 (aminoethyl) 3-aminopropyltrimethoxysilane, N-2 (aminoethyl) 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, decyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, vinyl, 3-aminopropyltriethoxysilane, 3-ureidopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane and the like, preferably 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, N-2 (aminoethyl) 3-aminopropylmethyldimethoxysilane, N-2 (aminoethyl) 3-aminopropyltrimethoxysilane, N-2 (aminoethyl) 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane and 3-aminopropyltriethoxysilane, and particularly preferably 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, and the like, 3-aminopropyl triethoxysilane or their combination.

Further, in the alcoholic solution of the silane coupling agent, the weight ratio of the silane coupling agent to the alcoholic solution is 1 (0.2-20), preferably 1: (0.5-10), particularly preferably 1: (1-4); wherein the alcohol is preferably one or more of methanol, ethanol, n-propanol, isopropanol and n-butanol, and particularly preferably ethanol or isopropanol or the combination of the two.

Further, the silane coupling agent is used in an amount of 0.1% to 10%, preferably 0.5% to 5%, particularly preferably 1% to 3% by dry weight of the mica.

The dropping speed of the silane coupling agent alcohol solution in the step (3) is 0.5h-12h, preferably 0.5 h-6 h, and particularly preferably 1 h-4 h.

Further, the mica seminal plasma is one or a combination of more of muscovite seminal plasma, phlogopite seminal plasma, calcined muscovite seminal plasma, calcined phlogopite seminal plasma and synthetic mica seminal plasma, and the particle size of the mica seminal plasma is distributed between-4 meshes and +120 meshes, preferably between-8 meshes and +100 meshes, and more preferably between-10 meshes and 80 meshes.

The mica fine pulp is prepared by one or more of hydraulic crushing pulping, squirrel-cage crushing pulping, wheel grinding crushing pulping and ultrasonic crushing pulping, and the hydraulic crushing pulping is preferred.

Further, the temperature in step (2) is from 40 ℃ to 90 ℃, preferably from 65 ℃ to 85 ℃, particularly preferably from 70 ℃ to 80 ℃, and the pH value is from 2 to 10, preferably from 3 to 8, particularly preferably from 4 to 8.

Further, the activated mica paper of step (5) has a reactive group chemically bonded to the organic material on the silane coupling agent.

Further, the adhesive used for sizing is one of an aqueous/oily silicone adhesive, a polyester adhesive, an epoxy resin adhesive, a polyurethane adhesive and a modified adhesive thereof, and preferably the silicone adhesive.

Furthermore, the reinforcing material is one or a combination of several of glass fiber cloth, non-woven fabric, polyester film and polyolefin film.

The invention has the following beneficial effects:

1. the invention adopts a chemical hydrolysis method to graft a silane coupling agent on the surface of a mica flake: alkoxy of the silane coupling agent is hydrolyzed and combined to the mica surface, so that functional groups capable of reacting with organic materials are generated on the mica surface, the polarity and reactivity of the mica surface are greatly increased, intermolecular acting force is enhanced, the silane coupling agent can be quickly infiltrated, compatible and reacted with an adhesive in the process of gluing a product, and the mechanical strength of the product is improved.

2. The coupling agent in the active mica paper prepared by the invention only accounts for less than 5% of the mass of mica, and the active mica paper has almost no influence on the insulativity of the mica and the heat resistance of the adhesive.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to specific embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1: active gold mica paper

Selecting imported Indian phlogopite, washing, conveying to a hydraulic crusher through a conveying machine, grading and concentrating, and pumping into a fine pulp tank, wherein the particle size distribution and the solid content of mica flakes are shown in table 1 through tests.

500kg of phlogopite seminal plasma was pumped into the reaction vessel, stirring was turned on and 650kg of water was added, then the steam was turned on and the mica suspension was heated to 70 ℃. After the temperature is stabilized, the pH value of the suspension is adjusted to 7.5 by 1:1 hydrochloric acid; weighing 2.1kg of KH550, dissolving in 6.3kg of ethanol, stirring uniformly for later use, adjusting the feeding speed of the coupling agent alcoholic solution to be 40ml/min, starting to dropwise add the coupling agent into the suspension, and adding acid to maintain the pH constant. After all the materials are added, discharging, filtering and washing to be neutral, adding water until the solid content of the mica is about 42%, and pumping to an active phlogopite seminal plasma pool.

According to the papermaking process, the active phlogopite is processed by papermaking, squeezing, baking and rolling to obtain the active phlogopite paper.

Example 2: activated calcined muscovite paper

Selecting imported muscovite, calcining at 800 ℃ for 1 hour, cooling to room temperature, conveying to a hydraulic crusher by a conveyor, grading and concentrating, and pumping into a seminal plasma pool, wherein the particle size distribution and solid content of mica flakes are shown in Table 1 through tests.

500kg of calcined muscovite concentrate was pumped into the reaction vessel, stirring was switched on and 850kg of water was added, then the steam was switched on and the mica suspension was heated to 80 ℃. After the temperature is stabilized, the pH value of the suspension is adjusted to 6.5 by 1:1 hydrochloric acid; weighing 2.5kg of KH560, dissolving in 5kg of ethanol, stirring uniformly for later use, adjusting the feeding speed of the coupling agent alcoholic solution to 40ml/min, starting to dropwise add the coupling agent into the suspension, and adding acid to maintain the pH constant. After all the materials are added, discharging, filtering and washing to be neutral, adding water until the solid content of the mica is about 42%, and pumping to an active calcined muscovite fine pulp tank.

According to the papermaking process, the active calcined muscovite is subjected to papermaking, squeezing, baking and rolling to obtain the active calcined muscovite paper.

Example 3: active synthetic mica paper

Selecting synthetic mica, conveying to a hydraulic crusher by a material conveying machine, grading and concentrating, and then pumping into a fine pulp tank. The particle size distribution and solids content of the mica flakes are shown in table 1.

500kg of synthetic mica magma were pumped into the reaction vessel, the stirring was switched on and 850kg of water was added, then the steam was switched on and the mica suspension was heated to 80 ℃. After the temperature is stabilized, the pH value of the suspension is adjusted to 5.5 by 1:1 hydrochloric acid; weighing 3kg of KH570, dissolving in 12kg of ethanol, stirring uniformly for later use, adjusting the feeding speed of the coupling agent alcoholic solution to be 50ml/min, starting to dropwise add the coupling agent into the suspension, and controlling the pH value. After all the materials are added, discharging, filtering and washing to be neutral, adding water until the solid content of the mica is about 42%, and pumping to an active synthetic mica fine pulp tank.

According to the papermaking process, the active synthetic mica is processed by papermaking, squeezing, baking and rolling to obtain the active synthetic mica paper.

Comparative example 4 conventional gold mica paper

Selecting imported Indian phlogopite, washing, conveying to a hydraulic crusher through a conveying machine, grading and concentrating, and pumping into a fine pulp tank, wherein the particle size distribution and the solid content of mica flakes are shown in table 1 through tests.

According to the papermaking process, the active phlogopite is processed by papermaking, squeezing, baking and rolling to obtain the conventional phlogopite paper.

Comparative example 5 conventional calcined muscovite paper

Selecting imported muscovite, calcining at 800 ℃ for 1 hour, cooling to room temperature, conveying to a hydraulic crusher by a conveyor, grading and concentrating, and pumping into a seminal plasma pool, wherein the particle size distribution and solid content of mica flakes are shown in Table 1 through tests.

According to the papermaking process, the calcined muscovite is subjected to papermaking, squeezing, baking and rolling to obtain the conventional calcined muscovite paper.

Comparative example 6 conventional synthetic mica paper

Selecting synthetic mica, conveying to a hydraulic crusher by a material conveying machine, grading and concentrating, and then pumping into a fine pulp tank. The particle size distribution and solids content of the mica flakes are shown in table 1.

According to the papermaking process, the synthetic mica is processed by papermaking, squeezing, baking and rolling to obtain the conventional synthetic mica paper.

TABLE 1 particle size distribution and solid content of mica flakes

Mica flake composition	Example 1	Example 2	Example 3	Comparative example 4	Comparative example 5	Comparative example 6
							> 8 mesh (%)	0	0	0	0	0	0
8-16 mesh (%)	0.5	0.4	0.4	0.5	0.4	0.4
							16-40 mesh (%)	31.15	33.34	35.27	31.15	33.35	35.26
40-80 mesh (%)	50.02	46.78	43.01	50.00	46.77	43.04
							80-100 mesh (%)	13.96	15.26	15.37	13.96	15.25	15.36
< 100 mesh (%)	4.37	4.22	5.95	4.37	4.23	5.96
							Mica content (%)	42.02	40.19	41.23	42.02	40.19	41.23

TABLE 2 mica paper Properties

As seen from the table, the treated mica paper has 40% or more of mechanical strength and 20% or more of puncture strength.

Example 7 reactive gold mica plate

Coating the mica paper prepared in the embodiment 1 on a conveying belt by an organic silicon adhesive, gluing, drying to obtain glued phlogopite paper, and weighting, pressing and cutting to obtain a phlogopite plate;

comparative example 8 conventional gold mica plate

Coating the mica paper prepared in the embodiment 4 on a conveying belt with an organic silicon adhesive, gluing, drying to obtain glued phlogopite paper, and weighting, pressing and cutting to obtain a phlogopite plate;

example 9 reactive gold mica tape

Compounding the mica paper prepared in the embodiment 1 with glass fibers soaked by an organic silicon adhesive on a conveying belt, drying to obtain a mica tape roll, and slitting to obtain a phlogopite tape;

comparative example 10 conventional phlogopite tape

Compounding the mica paper prepared in the embodiment 4 with glass fibers soaked by an organic silicon adhesive on a conveying belt, drying to obtain a mica tape roll, and slitting to obtain a phlogopite tape;

the comparison of the performances is shown in tables 3 and 4, and the comparison shows that the active mica paper and the product thereof are superior in mechanical property and insulating strength compared with the untreated product, and are respectively improved by more than 50 percent and 20 percent.

TABLE 3 comparison of mica board Properties

	Example 7	Comparative example 8
			Mica content (%)	92.2％	92.5％
Gel content (%)	7.8％	7.5％
			Weight loss at 500 deg.C (%)	0.8	0.8
Weight loss at 700 deg.C (%)	1.6	1.7
			Bending strength (N/mm)2)	230	153
Dielectric strength (kV/mm)	32	25

Table 4 comparison of mica tape properties

The invention adopts a chemical hydrolysis method to graft a silane coupling agent on the surface of a mica flake: alkoxy of the silane coupling agent is hydrolyzed and combined to the mica surface, so that functional groups capable of reacting with organic materials are generated on the mica surface, the polarity and reactivity of the mica surface are greatly increased, intermolecular acting force is enhanced, the silane coupling agent can be quickly infiltrated, compatible and reacted with an adhesive in the process of gluing a product, and the mechanical strength of the product is improved.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.