阅读说明：本技术 一种透气膜用助孔剂的制备工艺 (Preparation process of pore-assisting agent for breathable film ) 是由 李领欢 于 2021-02-05 设计创作，主要内容包括：本发明提供的一种透气膜用助孔剂的制备工艺,是优良的干法工艺,本发明先将原料粉体送入球磨设备中,将原料粉体与磨珠按比例混合,一同研磨,并将研磨后得到的研磨粉料送入改性主机中,与表面改性剂混合改性均化,研磨粉料在高温热风的环境下,其内含的水分被快速蒸发,且研磨粉料和表面改性剂在上部下压气流和下部高温热风两股气流的交织下形成的湍流中,改性剂快速熔化与原料粉体充分接触完成改性,改性均化效果好,得到的助孔剂的粒径小,粒径可控,粒径精准,粒度分布窄,具有较佳的可分散性,良好的热稳定性,良好的疏水性,优良的助孔效果,优异的加工性能和机械性能。(The invention provides a preparation process of a pore-assisting agent for a breathable film, which is an excellent dry process, the invention firstly feeds raw material powder into ball milling equipment, mixes the raw material powder and grinding beads in proportion, grinds the raw material powder and the grinding beads together, sending the ground powder obtained after grinding into a modification host machine, mixing with a surface modifier for modification and homogenization, and carrying out high-temperature hot air treatment on the ground powder, the moisture contained therein is rapidly evaporated, and the grinding powder and the surface modifier are in the turbulent flow formed under the interweaving of the upper and lower pressure air flows and the lower high temperature hot air flow, the modifier is quickly melted and fully contacted with the raw material powder to complete modification, the modification homogenization effect is good, the obtained pore-aiding agent has small particle size, controllable particle size, accurate particle size, narrow particle size distribution, better dispersibility, good thermal stability, good hydrophobicity, excellent pore-aiding effect and excellent processing performance and mechanical performance.)

1. A preparation process of a pore-assisting agent for a breathable film is characterized by comprising the following process steps:

s1, feeding the raw material powder into a ball milling device for grinding, and obtaining ground powder after grinding is finished;

s2, sending the grinding powder into a modification host machine, introducing high-temperature hot air into the bottom of the modification host machine, forming a downward-pressing air flow at the upper end of the modification host machine, sending a surface modifier into the modification host machine, wherein the coating amount of the added surface modifier is 0.9-1.1%, and modifying and homogenizing the grinding powder and the surface modifier under the high-temperature hot air environment and under the interweaving of two air flows of the upper downward-pressing air flow and the lower high-temperature hot air flow;

s3, after homogenization, sending the homogenized powder into dust collection equipment for dust collection;

s4, collecting dust to obtain powder, namely the pore-forming agent, wherein the moisture content is less than 0.1%, and the ignition loss is 0.9-1.1%.

2. The preparation process of the pore-assisting agent for the breathable film according to claim 1, wherein in a ball milling device, the mass ratio of raw material powder to grinding beads is 1: 4.

3. The process for preparing a pore promoter for breathable films according to claim 1, wherein in step S1, the particle size of the raw material powder added to the ball milling equipment is 3 mm.

4. The process for preparing a pore aid for breathable films according to claim 1, wherein in step S1, the obtained ground powder has a particle size D50 of 2.5 μm and a particle size D98 of 8 to 10 μm.

5. The process for preparing a pore promoter for breathable films according to claim 1, wherein the temperature of the high temperature hot air is 105-125 ℃ in step S2.

6. The process of claim 1, wherein in step S2, the surface modifier is plant-grade stearic acid obtained by secondary pressing.

[ technical field ] A method for producing a semiconductor device

The invention relates to the technical field of pore-assisting agents, in particular to a preparation process of a pore-assisting agent for a breathable film.

[ background of the invention ]

The breathable film has the unique functions of air permeability and water impermeability, so that the breathable film is famous and noisy in the markets of medical protective clothing, sanitary towels, paper urine, protective pads, medical surgical gowns and surgical drapes. The polyethylene breathable film is prepared by adding about 50% of special calcium carbonate, namely a pore-assisting agent, into a low-density polyethylene/linear low-density polyethylene resin carrier, blending, extruding to form a film, and then directionally stretching to a certain multiplying power.

Due to the difference of the production process, the wet-method and dry-method superfine heavy calcium carbonate have obvious difference in physical properties. Such as powder particle morphology, fineness, particle size distribution and the like. 1) The particle morphology is as follows: the wet-process superfine heavy calcium carbonate has good particle shape, most of the particles are spherical or approximately spherical, and the quality is stable. Therefore, the processing fluidity is good, the mechanical abrasion is small, and the wet-process ultrafine ground calcium carbonate has good processability even when added in a large proportion. Most of the heavy calcium carbonate produced by the dry method is amorphous and irregular, and the edges and corners of the particles are clear; 2) powder particle fineness: more than 90 percent of the wet-process superfine ground calcium carbonate particles have the particle size of 2 mu m, namely more than 6000 meshes, while the ground calcium carbonate produced by the dry process has the particle size of only 60 percent of the particles of 2 mu m, namely about 2000 meshes under the better condition; 3) powder particle size distribution: the wet-process superfine heavy calcium carbonate has narrow particle size distribution and uniform particle size, is generally concentrated below 2 mu m, and has a particle size distribution curve in a single-peak form; the particle size distribution curve of the superfine heavy calcium carbonate produced by the dry method is bimodal, the particle size distribution is wide, and the particle size distribution is mostly in the range of 1.0-10 mu m.

At present, the dry process powder is almost not used in the material products of the breathable film successfully, and the phenomena of agglomeration, no dispersion, more points and large smoke are easy to appear in the granulation, tape casting and film forming process, so that the product is thin and uneven in thickness and dispersion, easy to break holes, more in mouth mold coking and poor in effect, and the product of the wet process is monopolized by two foreign capital companies, large in investment and has a certain technical bottleneck.

In response to the above problems, we developed a new production process.

[ summary of the invention ]

The invention aims to overcome the defects of the prior art and provides a preparation process of a pore-forming aid for a breathable film.

In order to solve the technical problems, the invention adopts the following technical scheme:

a preparation process of a pore-assisting agent for a breathable film comprises the following process steps:

s1, feeding the raw material powder into a ball milling device for grinding, and obtaining ground powder after grinding is finished;

s2, sending the grinding powder into a modification host machine, introducing high-temperature hot air into the bottom of the modification host machine, forming a downward-pressing air flow at the upper end of the modification host machine, sending a surface modifier into the modification host machine, wherein the coating amount of the added surface modifier is 0.9-1.1%, and modifying and homogenizing the grinding powder and the surface modifier under the high-temperature hot air environment and under the interweaving of two air flows of the upper downward-pressing air flow and the lower high-temperature hot air flow;

s3, after homogenization, sending the homogenized powder into dust collection equipment for dust collection;

s4, collecting dust to obtain powder, namely the pore-forming agent, wherein the moisture content is less than 0.1%, and the ignition loss is 0.9-1.1%.

In a further improvement scheme, in the ball milling equipment, the mass ratio of the raw material powder to the milling beads is 1: 4.

In a further improvement, in step S1, the particle size of the raw material powder added to the ball milling device is 3 mm.

In a further refinement, in step S1, the resulting ground powder has a particle size D50 of 2.5 μm and D98 of 8 to 10 μm.

In a further modification, in step S2, the temperature of the high-temperature hot air is 105-125 ℃.

In a further modification, in step S2, the surface modifier is a secondary pressed plant-grade stearic acid.

Compared with the prior art, the invention has the beneficial effects that: the invention provides a preparation process of a pore-assisting agent for a breathable film, which is an excellent dry process, the invention firstly feeds raw material powder into ball milling equipment, mixes the raw material powder and grinding beads in proportion, grinds the raw material powder and the grinding beads together, sending the ground powder obtained after grinding into a modification host machine, mixing with a surface modifier for modification and homogenization, and carrying out high-temperature hot air treatment on the ground powder, the moisture contained in the grinding powder is quickly evaporated, and the grinding powder and the surface modifier are in turbulent flow formed under the interweaving of the upper part lower pressure air flow and the lower part high temperature hot air flow, the modifier is quickly melted and fully contacted with the raw material powder to complete modification, the modification homogenization effect is good, the obtained pore-aiding agent has small particle size, controllable particle size, accurate particle size, narrow particle size distribution, better dispersibility, good thermal stability, good hydrophobicity, excellent pore-aiding effect and excellent processing performance and mechanical performance.

[ detailed description ] embodiments

To better illustrate the objects, aspects and advantages of the present invention, the present invention will be further described with reference to specific examples.

A preparation process of a pore-assisting agent for a breathable film comprises the following process steps:

s1, feeding the raw material powder into a ball milling device for grinding, and obtaining ground powder after grinding is finished;

s2, sending the grinding powder into a modification host machine, introducing high-temperature hot air into the bottom of the modification host machine, forming a downward-pressing air flow at the upper end of the modification host machine, sending a surface modifier into the modification host machine, wherein the coating amount of the added surface modifier is 0.9-1.1%, and modifying and homogenizing the grinding powder and the surface modifier under the high-temperature hot air environment and under the interweaving of two air flows of the upper downward-pressing air flow and the lower high-temperature hot air flow;

s3, after homogenization, sending the homogenized powder into dust collection equipment for dust collection;

s4, collecting dust to obtain powder, namely the pore-forming agent, wherein the moisture content is less than 0.1%, and the ignition loss is 0.9-1.1%.

In a further improvement scheme, in the ball milling equipment, the mass ratio of the raw material powder to the grinding beads is 1:4, and the grinding fineness is achieved by controlling the ratio of the raw material powder to the grinding beads.

In a further improvement, in step S1, the particle size of the raw material powder added to the ball milling device is 3 mm.

In a further refinement, in step S1, the resulting ground powder has a particle size D50 of 2.5 μm and D98 of 8 to 10 μm.

In a further modification, in step S2, the temperature of the high-temperature hot air is 105-125 ℃.

In a further improvement, in step S2, the surface modifier is plant-grade stearic acid which is pressed in the second stage and has good temperature resistance and activity.

Test detection

The prepared pore-assisting agent is detected, and the specific detection results are as follows:

the invention firstly feeds the raw material powder into ball milling equipment, mixes the raw material powder and milling beads according to a certain proportion, grinds the raw material powder and the milling beads together, sending the ground powder obtained after grinding into a modification host machine, mixing with a surface modifier for modification and homogenization, and carrying out high-temperature hot air treatment on the ground powder, the moisture contained in the grinding powder is quickly evaporated, and the grinding powder and the surface modifier are in turbulent flow formed under the interweaving of the upper part lower pressure air flow and the lower part high temperature hot air flow, the modifier is quickly melted and fully contacted with the raw material powder to complete modification, the modification homogenization effect is good, the obtained pore-aiding agent has small particle size, controllable particle size, accurate particle size, narrow particle size distribution, better dispersibility, good thermal stability, good hydrophobicity, excellent pore-aiding effect and excellent processing performance and mechanical performance, and therefore, the preparation process provided by the invention is an excellent dry process.

Although the present invention has been described in detail with reference to the above embodiments, it will be apparent to those skilled in the art from this disclosure that various changes or modifications can be made herein without departing from the principles and spirit of the invention as defined by the appended claims. Therefore, the detailed description of the embodiments of the present disclosure is to be construed as merely illustrative, and not limitative of the remainder of the disclosure, but rather to limit the scope of the disclosure to the full extent set forth in the appended claims.