阅读说明：本技术 一种湿法造纸涂布浆料液的制备方法 (Preparation method of wet papermaking coating slurry liquid ) 是由 宋微 李磊 李铁民 刘玉海 范虹 杨升旗 于 2020-06-17 设计创作，主要内容包括：一种湿法造纸涂布浆料液的制备方法,该方法是以滑石和水镁石复合粉体为主要原料,具体方法包括：将滑石和水镁石块料破碎成20mm以下渣料,混合后用雷蒙磨研制成150-200目的粗粉,然后在粉体中加入润湿剂、降粘剂和水调制成浆料液,再送入球磨机进行研磨,研磨过程中添加助磨剂六偏磷酸钠,研磨出来的浆料液经筛网过滤后,灌装为成品储存起来；所述助磨剂的添加量为滑石与水镁石复合粉体的0.05wt％-0.08wt％。本发明采用的是块料水镁石,研磨之后会成为片状,其性质与滑石相近,剥片性好,长径比高,白度高,在水中的分散性好,块料水镁石的这些性能恰好弥补了滑石用于造纸涂料的一些不足之处。(A preparation method of wet paper-making coating slurry liquid takes talcum and brucite composite powder as main raw materials, and the specific method comprises the following steps: crushing talc and brucite blocks into slag materials with the particle size of less than 20mm, mixing the slag materials, grinding the slag materials into coarse powder with the particle size of 150-plus-200 meshes by using a Raymond mill, adding a wetting agent, a viscosity reducer and water into the powder to prepare slurry liquid, then feeding the slurry liquid into a ball mill for grinding, adding a grinding aid sodium hexametaphosphate in the grinding process, filtering the ground slurry liquid by using a screen, and filling the slurry liquid into a finished product to be stored; the addition amount of the grinding aid is 0.05-0.08 wt% of the talc and brucite composite powder. The lump brucite adopted by the invention can be formed into a sheet shape after being ground, the property of the lump brucite is similar to that of talc, the sheet stripping property is good, the length-diameter ratio is high, the whiteness is high, the dispersibility in water is good, and the properties of the lump brucite just make up for some defects of the talc used for paper-making coating.)

1. The preparation method of the wet papermaking coating slurry liquid is characterized in that the method takes talc and brucite composite powder as main raw materials, and the specific method comprises the following steps: crushing talc and brucite blocks into slag materials with the particle size of less than 20mm, mixing the slag materials, grinding the slag materials into coarse powder with the particle size of 150-plus-200 meshes by using a Raymond mill, adding a wetting agent, a viscosity reducer and water into the powder to prepare slurry liquid, then feeding the slurry liquid into a ball mill for grinding, adding a grinding aid sodium hexametaphosphate in the grinding process, filtering the ground slurry liquid by using a screen, and filling the slurry liquid into a finished product to be stored; the addition amount of the grinding aid is 0.05-0.08 wt% of the talc and brucite composite powder.

2. The preparation method of the coating slurry liquid for wet papermaking according to claim 1, wherein the whiteness of the talc is not less than 90, and the loss on ignition is not more than 6.5%; the whiteness of brucite is more than or equal to 93, and the purity is more than or equal to 69%.

3. The preparation method of coating slurry liquid for wet papermaking according to claim 1, wherein the mixing mass ratio of the talc coarse powder to the brucite coarse powder is 80-90: 10-20.

4. The preparation method of the coating slurry liquid for wet papermaking according to claim 1, wherein the addition amount of water is 43-50 wt% of the talc and brucite composite powder; the wetting agent adopts alkylphenol polyoxyethylene, and the addition amount of the alkylphenol polyoxyethylene is 0.05 to 0.13 weight percent of the talc and brucite composite powder; the viscosity reducer adopts polydimethylsiloxane dispersoid, and the addition amount of the viscosity reducer is 0.03 to 0.07 percent of the talc and brucite composite powder by weight.

Technical Field

The invention relates to the technical field of preparation of papermaking coatings, in particular to a preparation method of talc powder wet papermaking coating slurry liquid.

Background

The coating paper in China has a wide market and large demand on the coating, and the existing coating takes high-end kaolin as a main raw material, but the high-end kaolin has low yield and high price, and many enterprises cannot bear high cost. Sometimes domestic coatings are not available and many paper mills rely on imported coatings. Therefore, there is a strong need for a low-cost and high-yield material to replace the existing coating material.

Research shows that, in the application of paper-making paint, talcum powder can completely or partially replace kaolin which is rare in domestic resources and expensive in price. The talc is used as a coating pigment, has better fiber covering capacity and printing effect, can improve the whiteness, opacity, smoothness and printing glossiness of coated paper, endows the paper with higher ink absorption, and improves the gravure printing quality. And talc has lubricity, and coated paper made therefrom can achieve a high degree of finish on a calender and can reduce the amount of lubricant used in the coating.

China is a country with large talc output, and talc has the advantages of good quality, high whiteness, flaky structure, low price, soft material and low abrasion. In view of these characteristics, talc is well suited as a substitute for kaolin. However, the powder of the paper making coating is ultrafine powder, the solid content requirement of the paper making coating is high, and the talcum is oleophilic and hydrophobic. These reasons have led to the difficulty of dispersing talc powder in water to give high solids, low viscosity coatings. Therefore, the dispersibility of talc must be improved to make it a paper coating.

In addition, the talcum powder with higher fineness is processed on an air current mill at present, so that a good peeling effect on the talcum powder cannot be formed, and a complete talcum sheet structure cannot be reserved.

Disclosure of Invention

The invention aims to provide a preparation method of a wet papermaking coating slurry liquid, which comprises the steps of crushing talc and brucite by a crusher, mixing the crushed talc and brucite according to a certain proportion, grinding the mixture into coarse powder in a Raymond mill, wetting, reducing viscosity and the like, dispersing the coarse powder into the slurry liquid, then feeding the slurry liquid into a ball mill for wet grinding, adding a grinding aid in the grinding process, and finally grinding the slurry liquid to obtain the high-solid-content and low-viscosity composite powder slurry liquid with the particle fineness and the lamellar structure meeting the requirements of papermaking coating.

In order to achieve the purpose, the invention adopts the following technical scheme:

a preparation method of wet paper-making coating slurry liquid takes talcum and brucite composite powder as main raw materials, and the specific method comprises the following steps: crushing talc and brucite blocks into slag materials with the particle size of less than 20mm, mixing the slag materials, grinding the slag materials into coarse powder with the particle size of 150-plus-200 meshes by using a Raymond mill, adding a wetting agent, a viscosity reducer and water into the powder to prepare slurry liquid, then feeding the slurry liquid into a ball mill for grinding, adding a grinding aid sodium hexametaphosphate in the grinding process, filtering the ground slurry liquid by using a screen, and filling the slurry liquid into a finished product to be stored; the addition amount of the grinding aid is 0.05-0.08 wt% of the talc and brucite composite powder.

The whiteness of the talc is more than or equal to 90 percent, and the ignition loss is less than or equal to 6.5 percent; the whiteness of brucite is more than or equal to 93, and the purity is more than or equal to 69%.

The mixing mass ratio of the talc coarse powder to the brucite coarse powder is 80-90: 10-20.

The addition amount of the water is 43 to 50 weight percent of the talc and brucite composite powder; the wetting agent adopts alkylphenol polyoxyethylene, and the addition amount of the alkylphenol polyoxyethylene is 0.05 to 0.13 weight percent of the talc and brucite composite powder; the viscosity reducer adopts polydimethylsiloxane dispersoid, and the addition amount of the viscosity reducer is 0.03 to 0.07 percent of the talc and brucite composite powder by weight.

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

the lump brucite adopted by the invention can be formed into a sheet shape after being ground, the property of the lump brucite is similar to that of talc, the sheet stripping property is good, the length-diameter ratio is high, the whiteness is high, the dispersibility in water is good, and the properties of the lump brucite just make up for some defects of the talc used for paper-making coating.

The brucite and the talc are compounded according to a certain proportion, so that the dispersion difficulty of talc powder can be reduced, the solid content of the coating liquid is improved, and some defects of the talc on a coating surface layer are overcome; the composite powder is dispersed into slurry liquid to be ball-milled and ground by a wet method, so that the lamellar structure of the powder can be retained to the maximum extent; the liquid medicine is added into the powder before grinding to improve the dispersibility, so that the fineness of wet grinding is greatly improved, and further excellent coating performance is obtained; the wet grinding reduces the dust pollution to the environment, completes the preparation of the coating in the grinding process, reduces the steps of the preparation of the coating in a paper mill, and ensures that the whole operation is simpler and more reasonable in the allocation of industrial resources.

The solid content of the finished coating slurry liquid is more than 66 wt%, the viscosity is less than or equal to 270 centipoises, the pH value is 7-8, the particle size of the largest particles of the powder in the slurry liquid is not more than 5 micrometers, and the content of the particle size below 2 micrometers is not less than 85 wt%.

Drawings

FIG. 1 is a process flow diagram of the present invention.

Detailed Description

The present invention will be described in detail below, but the scope of the present invention is not limited to the following embodiments.

A preparation method of wet paper-making coating slurry liquid takes talcum and brucite composite powder as main raw materials, and the specific method comprises the following steps: crushing talc and brucite blocks into slag materials with the particle size of less than 20mm, mixing the slag materials, grinding the slag materials into coarse powder with the particle size of 150-plus-200 meshes by using a Raymond mill, adding a wetting agent, a viscosity reducer and water into the powder to prepare slurry liquid, then feeding the slurry liquid into a ball mill for grinding, adding a grinding aid sodium hexametaphosphate in the grinding process, filtering the ground slurry liquid by using a screen, and filling the slurry liquid into a finished product to be stored; the addition amount of the grinding aid is 0.05-0.08 wt% of the talc and brucite composite powder.

The whiteness of the talc is more than or equal to 90 percent, and the ignition loss is less than or equal to 6.5 percent; the whiteness of brucite is more than or equal to 93, and the purity is more than or equal to 69%.

The mixing mass ratio of the talc coarse powder to the brucite coarse powder is 80-90: 10-20.

The addition amount of the water is 43 to 50 weight percent of the talc and brucite composite powder; the wetting agent adopts alkylphenol polyoxyethylene, and the addition amount of the alkylphenol polyoxyethylene is 0.05 to 0.13 weight percent of the talc and brucite composite powder; the viscosity reducer adopts polydimethylsiloxane dispersoid, and the addition amount of the viscosity reducer is 0.03 to 0.07 percent of the talc and brucite composite powder by weight.

The invention adopts talc and brucite as composite raw materials. Brucite is less hydrophobic than talc, which is beneficial to the dispersion of the whole powder in water. Crushing brucite lump materials and talc lump materials by a crusher, mixing according to a certain proportion, grinding by a Raymond mill to obtain coarse powder with the particle size of 150 plus 200 meshes, and finally preparing the composite powder slurry with high solid content and low viscosity according with the particle fineness and the lamellar structure of the papermaking coating liquid by processing steps of chemical modification, wet grinding, filtering and the like. Sodium hexametaphosphate is added in the grinding process, so that the subsequent fineness of the powder is improved.