阅读说明：本技术 一种膏状隔离剂及其制备和使用方法 (Paste-like separant and preparation and use methods thereof ) 是由 赵会岩 赵海林 张志胜 张玉红 于 2021-03-04 设计创作，主要内容包括：本发明涉及膏状隔离剂技术领域,膏状隔离剂的制备步骤：S1、凹凸棒土和蒙脱土研磨获得第一混合物；S2、第一混合物等离子处理获得第二混合物；S3、第二混合物清洗,烘干后获得第三混合物；S4、加入稀盐酸,超声分散,获得第一分散液；S5、氢氧化钠溶液将pH值调节为4～5,获得第二分散液；S6、硅烷偶联剂加入第二分散液,超声分散,洗涤、过滤、干燥后获得改性凹凸棒土/蒙脱土混合物；S7、阳离子表面活性剂加入去离子水中,依次加入改性凹凸棒土/蒙脱土混合物和增稠剂,搅拌分散获得膏状隔离剂。本发明提供的膏状隔离剂,用量少,隔离效果好、分散性和吸附性好,不易沉降,环保无污染。(The invention relates to the technical field of paste separants, which comprises the following steps: s1, grinding attapulgite and montmorillonite to obtain a first mixture; s2, carrying out plasma treatment on the first mixture to obtain a second mixture; s3, cleaning the second mixture, and drying to obtain a third mixture; s4, adding dilute hydrochloric acid, and performing ultrasonic dispersion to obtain a first dispersion liquid; s5, adjusting the pH value to 4-5 by using a sodium hydroxide solution to obtain a second dispersion liquid; s6, adding a silane coupling agent into the second dispersion liquid, performing ultrasonic dispersion, washing, filtering and drying to obtain a modified attapulgite/montmorillonite mixture; and S7, adding a cationic surfactant into deionized water, sequentially adding the modified attapulgite/montmorillonite mixture and the thickening agent, and stirring and dispersing to obtain the pasty separant. The pasty separant provided by the invention has the advantages of small using amount, good isolation effect, good dispersibility and adsorbability, difficult settlement, environmental protection and no pollution.)

1. The preparation method of the paste separant is characterized by comprising the following steps of:

s1, grinding attapulgite and montmorillonite in a grinder and then sieving to obtain a first mixture with the particle size of 200-800 nanometers;

s2, putting the first mixture obtained in the S1 into an arc plasma generator, and carrying out plasma treatment for 5-10 minutes under the direct-current voltage of 30-50 kV to obtain a second mixture;

s3, adding the second mixture obtained in the step S2 into deionized water, stirring and dispersing, standing and precipitating, filtering out precipitates, repeatedly cleaning the precipitates for 3-5 times according to the operation, and drying to obtain a third mixture;

step S4 of adding the third mixture obtained in step S3 to a dilute hydrochloric acid solution, and ultrasonically dispersing the mixture at 70 ± 5 ℃ for 1 hour by an ultrasonic emulsion disperser to obtain a first dispersion liquid;

s5, dropwise adding a sodium hydroxide solution into the first dispersion liquid obtained in the S4, and adjusting the pH value of the first dispersion liquid to 4-5 to obtain a second dispersion liquid;

step S6, adding a silane coupling agent into the second dispersion liquid obtained in the step S5, ultrasonically dispersing for 1-2 hours by using an ultrasonic emulsification disperser, washing, filtering and drying to obtain a modified attapulgite/montmorillonite mixture;

and step S7, adding the cationic surfactant into deionized water, stirring and dissolving, then sequentially adding the modified attapulgite/montmorillonite mixture obtained in the step S6 and the thickening agent, stirring and dispersing for 30 minutes at the rotating speed of 3000 revolutions per minute, and adding a proper amount of defoaming agent for defoaming during stirring to obtain the pasty isolating agent.

2. The method of claim 1, wherein the concentration of the dilute hydrochloric acid solution in step S4 is 0.5-1 wt%; the concentration of the sodium hydroxide solution in the step S5 is 10-15 wt%.

3. The method for preparing the paste release agent according to claim 1, wherein when the ultrasonic emulsification disperser performs ultrasonic dispersion, the ultrasonic power is 200-500W, and the ultrasonic frequency is 20-25 kHz.

4. The method of claim 1, wherein said silane coupling agent in step S6 is at least one of vinyltriethoxysilane, vinyltrimethoxysilane and vinyltris (β -methoxyethoxy) silane.

5. The method of claim 1, wherein the cationic surfactant in step S7 is at least one of octadecyl trimethyl ammonium bromide, octadecyl trimethyl ammonium chloride, hexadecyl trimethyl ammonium bromide and hexadecyl trimethyl ammonium chloride.

6. The method of claim 1, wherein said thickening agent in step S7 is sodium alginate.

7. The method for preparing a pasty release agent according to claim 1,

in the step S1, the attapulgite and the montmorillonite are mixed according to the ratio of (2-8): 1 in a mass ratio;

in step S3, mixing the second mixture with the deionized water in a ratio of 1: (10-12) mixing in a mass ratio;

in step S4, mixing the third mixture with the dilute hydrochloric acid solution in a ratio of 1: (2-3) mixing in a mass ratio;

the silane coupling agent is added in an amount of 2.5 to 3.5wt% of the third mixture in step S3 in step S6;

in step S7, mixing the modified attapulgite/montmorillonite mixture, the cationic surfactant, the deionized water, and the thickener in a ratio of 100: (16-25): (500-650): (3-12) in a mass ratio.

8. A paste release agent, characterized by being prepared by the method of any one of claims 1 to 7.

9. The use of the pasty release agent according to claim 8, comprising the steps of:

step S100, filling a paste separant into a spherical first container, wherein the first container is provided with small holes of 1-5 mm;

step S300, dividing the cooling water tank into an upper water tank layer and a lower water tank layer through a detachable grid, wherein a plurality of stirring devices are arranged in the lower water tank layer, are respectively arranged at the bottom and the side wall of the lower water tank layer and can be opened respectively or simultaneously;

step S500, placing one or more first containers in the step S100 into the lower layer of the cooling water tank in the step S300, wherein the first containers float on the lower layer along with the stirring of the stirring device, and the pasty isolating agent is gradually dissolved and diluted from the small holes along with the floating of the first containers and is diffused to the upper layer of the cooling water tank;

and S700, immersing the film into the upper layer of the water tank, coating a release agent, airing and stacking.

10. The use of the pasty release agent according to claim 8, comprising the steps of:

step S200, filling the pasty isolation agent into a second container with an opening at one end, wherein a cover body is arranged at the opening of the second container, and small holes of 1-5 mm are respectively formed in the side wall of the second container and the cover body;

s400, dividing a cooling water tank into an upper water tank layer and a lower water tank layer through a detachable grid, wherein the bottom of the lower water tank layer is provided with a rotating disc capable of horizontally rotating;

step S600, fixing one or more second containers in the step S200 on a rotating disc of the cooling water tank in the step S400, and gradually dissolving and diluting the pasty isolating agent from the small holes along with the rotation of the rotating disc and diffusing the pasty isolating agent to the upper layer of the water tank;

and step S800, immersing the film into the upper layer of the water tank, coating the isolating agent, airing and stacking.

Technical Field

The invention relates to the technical field of paste separants, in particular to a paste separant and a preparation method and a use method thereof.

Background

In the processing process of the rubber, the special self-adhesiveness of the rubber brings great inconvenience to large-scale industrial production, and particularly causes great troubles to the handling and reprocessing of the mixing rubber and the plasticated rubber. To reduce the trouble, rubber product manufacturers often apply a release agent to the rubber sheets before the rubber compound is finally formed into a finished product, such as before the rubber compound is handled, stored and transported, and extruded, and heated to prevent the rubber sheets from sticking to each other.

The mechanism of action of the release agent is: the method utilizes the larger difference of the mutual solubility of the separant and the rubber, and after the rubber films are dip-coated with the separant, a thin isolating layer is formed between the rubber films to block or slow down the mutual adhesion between the rubber films, thereby facilitating the process operation.

The material used as the rubber film release agent must meet the following requirements: the rubber film has a certain difference with the solubility coefficient of rubber, has high safety, no toxicity, no harm to human health and no pollution to the environment, and can form an isolation layer on the surface of the rubber film so as to have good isolation effect; the negative influence on the physical and mechanical properties of the rubber product is small; the process is convenient to operate.

The isolating agent widely used at present mainly comprises three forms of powder, liquid and paste.

The powder isolating agent has good isolating effect, but can bring about the problem of flying dust during use, and the automatic powder feeding device can reduce the pollution of dust but cannot completely solve the problem.

The liquid release agent has excellent wettability, but the coating concentration thereof is difficult to control. The film having a smooth surface is difficult to handle in a factory after being coated with the liquid release agent, and the solution is dropped on an operation site to cause an accident, and the liquid release agent is often overflowed from the screw of the extruder during the next processing of the film.

The paste separant has good separant effect, can not cause dust pollution, can also effectively control the coating concentration, avoids the sagging phenomenon, and is a more common separant form at present. However, the paste-like isolating agent needs advanced stepwise dilution when in use, is complex to operate, has unsatisfactory dispersibility in water, is easy to form sediment, reduces the effective utilization rate of the isolating agent, and influences the isolating effect.

Patent document No. CN104987519B discloses a paste water-based release agent, a preparation method and an application method thereof, wherein inorganic powder, a thixotropic agent and a thickening agent are sequentially added into an aqueous solution containing an anionic surfactant and a nonionic surfactant, and the mixture is stirred and ground to obtain the release agent. The inorganic powder in the method adopts superfine heavy calcium carbonate, superfine active zinc oxide, titanium dioxide and diatomite. Although the particle size is controlled, the problems of agglomeration and sedimentation are more likely to occur due to poor dispersibility of the nanoscale powder, and an anti-sedimentation agent is needed to relieve the sedimentation speed when the nano-scale powder is used, but the relieving effect is limited. In addition, the formula components of the release agent are too complex, so that excessive impurities are easily introduced in the subsequent processing process of the film, and the performance of a final product is influenced.

In conclusion, the paste separant which is simple in formula, good in isolation effect, good in dispersity and not prone to sedimentation is very necessary.

Disclosure of Invention

The present invention is directed to solving at least one of the above problems.

Therefore, the first purpose of the invention is to provide a preparation method of the pasty release agent.

The second purpose of the invention is to provide a paste-like release agent.

The third purpose of the invention is to provide a using method of the paste release agent.

In order to achieve the first object of the present invention, an embodiment of the present invention provides a preparation method of a paste-like release agent, including the following steps:

s1, grinding attapulgite and montmorillonite in a grinder and then sieving to obtain a first mixture with the particle size of 200-800 nanometers;

s2, putting the first mixture obtained in the S1 into an arc plasma generator, and carrying out plasma treatment for 5-10 minutes under the direct-current voltage of 30-50 kV to obtain a second mixture;

s3, adding the second mixture obtained in the step S2 into deionized water, stirring and dispersing, standing and precipitating, filtering out precipitates, repeatedly cleaning the precipitates for 3-5 times according to the operation, and drying to obtain a third mixture;

step S4, adding the third mixture obtained in the step S3 into a dilute hydrochloric acid solution, and ultrasonically dispersing for 1 hour at 70 +/-5 ℃ by using an ultrasonic emulsion disperser to obtain a first dispersion liquid;

s5, dropwise adding a sodium hydroxide solution into the first dispersion liquid obtained in the S4, and adjusting the pH value of the first dispersion liquid to 4-5 to obtain a second dispersion liquid;

step S6, adding a silane coupling agent into the second dispersion liquid obtained in the step S5, ultrasonically dispersing for 1-2 hours by using an ultrasonic emulsification disperser, washing, filtering and drying to obtain a modified attapulgite/montmorillonite mixture;

and step S7, adding the cationic surfactant into deionized water, stirring and dissolving, then sequentially adding the modified attapulgite/montmorillonite mixture obtained in the step S6 and the thickening agent, stirring and dispersing for 30 minutes at the rotating speed of 3000 revolutions per minute, and adding a proper amount of defoaming agent for defoaming during stirring to obtain the pasty isolating agent.

Preferably, the concentration of the dilute hydrochloric acid solution in the step S4 is 0.5-1 wt%; the concentration of the sodium hydroxide solution in the step S5 is 10-15 wt%.

Preferably, when the ultrasonic emulsification disperser carries out ultrasonic dispersion, the ultrasonic power is 200-500W, and the ultrasonic frequency is 20-25 kHz.

Preferably, the silane coupling agent in step S6 is at least one of vinyltriethoxysilane, vinyltrimethoxysilane and vinyltris (β -methoxyethoxy) silane.

Preferably, the cationic surfactant in step S7 is at least one of octadecyl trimethyl ammonium bromide, octadecyl trimethyl ammonium chloride, hexadecyl trimethyl ammonium bromide and hexadecyl trimethyl ammonium chloride.

Preferably, the thickener in step S7 is sodium alginate.

Preferably, the first and second liquid crystal materials are,

in the step S1, the attapulgite and the montmorillonite are mixed according to the ratio of (2-8): 1 in a mass ratio;

in step S3, mixing the second mixture with the deionized water in a ratio of 1: (10-12) mixing in a mass ratio;

in step S4, mixing the third mixture with the dilute hydrochloric acid solution in a ratio of 1: (2-3) mixing in a mass ratio;

the silane coupling agent is added in an amount of 2.5 to 3.5wt% of the third mixture in step S3 in step S6;

in step S7, mixing the modified attapulgite/montmorillonite mixture, the cationic surfactant, the deionized water, and the thickener in a ratio of 100: (16-25): (500-650): (3-12) in a mass ratio.

In order to achieve the second object of the present invention, the embodiment of the present invention provides a paste-like release agent, which is prepared by the above-mentioned preparation method of the paste-like release agent.

To achieve the third object of the present invention, an embodiment of the present invention provides a method for using a paste-like release agent, including the following steps:

step S100, filling a paste separant into a spherical first container, wherein the first container is provided with small holes of 1-5 mm;

step S300, dividing the cooling water tank into an upper water tank layer and a lower water tank layer through a detachable grid, wherein a plurality of stirring devices are arranged in the lower water tank layer, are respectively arranged at the bottom and the side wall of the lower water tank layer and can be opened respectively or simultaneously;

step S500, placing one or more first containers in the step S100 into the lower layer of the cooling water tank in the step S300, wherein the first containers float on the lower layer along with the stirring of the stirring device, and the pasty isolating agent is gradually dissolved and diluted from the small holes along with the floating of the first containers and is diffused to the upper layer of the cooling water tank;

and S700, immersing the film into the upper layer of the water tank, coating a release agent, airing and stacking.

To achieve the third object of the present invention, an embodiment of the present invention provides a method for using a paste-like release agent, including the following steps:

step S200, filling the pasty isolation agent into a second container with an opening at one end, wherein a cover body is arranged at the opening of the second container, and small holes of 1-5 mm are respectively formed in the side wall of the second container and the cover body;

s400, dividing a cooling water tank into an upper water tank layer and a lower water tank layer through a detachable grid, wherein the bottom of the lower water tank layer is provided with a rotating disc capable of horizontally rotating;

step S600, fixing one or more second containers in the step S200 on a rotating disc of the cooling water tank in the step S400, and gradually dissolving and diluting the pasty isolating agent from the small holes along with the rotation of the rotating disc and diffusing the pasty isolating agent to the upper layer of the water tank;

and step S800, immersing the film into the upper layer of the water tank, coating the isolating agent, airing and stacking.

Compared with the prior art, the invention has the following beneficial technical effects: the attapulgite and the montmorillonite are ground to obtain nanoscale mixture particles, so that the comprehensive use performance of the mixture particles is improved, and then the surface of the mixture particles is modified to improve the dispersibility of the mixture particles. The modification path is plasma activation-acid modification-sodium salt modification-silane coupling agent modification. The four modification modes have synergistic effect, so that the modification effect is greatly improved, and the modified attapulgite/montmorillonite mixture with high dispersibility is obtained. In the modification process, firstly, the attapulgite and the montmorillonite are activated by adopting an arc plasma method, and the Van der Waals force between the attapulgite and the montmorillonite and the bonding force of other ionic bonds are destroyed, so that the structure of the attapulgite and the montmorillonite becomes loose, and the comprehensive performance, the efficiency of subsequent process operation and the modification completion degree are greatly improved. The activated attapulgite and montmorillonite are washed by water, soluble impurities and inorganic salts are removed preliminarily, and the purity of the attapulgite and montmorillonite is improved. The plasma activated attapulgite and montmorillonite have loose structures, which is beneficial to ion exchange between cations, and the dilute hydrochloric acid solution is adopted for acidification modification, so that the collapse of a microstructure can be prevented, and the stability of the molecular structure of the attapulgite and montmorillonite is ensured. When the acidification is carried out, ultrasonic treatment is matched, so that the intermolecular motion frequency can be effectively improved, the cation exchange speed is enhanced, and the acidification modification efficiency and the acidification modification completion degree are improved. And adjusting the pH value of the acidified and modified first dispersion liquid by adopting a sodium hydroxide solution. The sodium hydroxide solution reacts with the dilute hydrochloric acid to produce sodium chloride and water, so that the pH value in the modification process can be effectively controlled, the modification environment is kept to be weakly acidic, the generated sodium salt can be used for carrying out secondary modification on the attapulgite and the montmorillonite, and meanwhile, the weakly acidic environment is also beneficial to the subsequent modification of the silane coupling agent. Under the action of ultrasonic wave, the acidification modification, the sodium salt modification and the silane coupling agent modification are carried out synergistically, and the modification completion degree is further improved. The obtained modified attapulgite/montmorillonite mixture has excellent dispersibility and comprehensive performance.

The modified attapulgite/montmorillonite mixture is dispersed in the water solution containing the cationic surfactant, so that the dispersibility of the modified attapulgite/montmorillonite in water and the compatibility of the modified attapulgite/montmorillonite with the thickening agent can be further improved. When the isolation agent is used, the coating uniformity and thickness of the isolation agent can be judged according to the self color of the dried attapulgite and montmorillonite, and the isolation effect meeting the storage requirement can be obtained by a small amount of isolation agent. In the subsequent processing process of the rubber sheet, the attapulgite and the montmorillonite are used as the nano-grade filler to be dispersed in the rubber product, so that the mechanical property, the flame retardant property and the thermal stability of the rubber product can be improved.

In conclusion, the paste separant provided by the invention is small in dosage, good in isolation effect, good in dispersity and adsorbability, not easy to settle, environment-friendly and pollution-free.

Drawings

FIG. 1 is a schematic view showing the structure of a first vessel and a cooling water tank in example 4;

FIG. 2 is a schematic view showing the structure of a second vessel and a cooling water tank in example 5.

Description of reference numerals:

101. a first container 201, a second container 202, a cover 301, a cooling water tank 302, a grating 303, an upper water tank layer 304, a lower water tank layer 305, a stirring device 401 and a rotary disc.

Detailed Description

The following description of the embodiments of the present invention refers to the accompanying drawings and examples:

in order that the above objects, features and advantages of the present invention can be more clearly understood, the present invention will be described in further detail with reference to specific embodiments. It should be noted that the embodiments and features of the embodiments of the present application may be combined with each other without conflict.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, however, the present invention may be practiced in other ways than those specifically described herein, and therefore the scope of the present invention is not limited by the specific embodiments disclosed below.

The embodiment of the invention provides a preparation method of a paste separant, which comprises the following steps:

s1, grinding attapulgite and montmorillonite in a grinder and then sieving to obtain a first mixture with the particle size of 200-800 nanometers;

s2, putting the first mixture obtained in the S1 into an arc plasma generator, and carrying out plasma treatment for 5-10 minutes under the direct-current voltage of 30-50 kV to obtain a second mixture;

s3, adding the second mixture obtained in the step S2 into deionized water, stirring and dispersing, standing and precipitating, filtering out precipitates, repeatedly cleaning the precipitates for 3-5 times according to the operation, and drying to obtain a third mixture;

step S4, adding the third mixture obtained in the step S3 into a dilute hydrochloric acid solution, and ultrasonically dispersing for 1 hour at 70 +/-5 ℃ by using an ultrasonic emulsion disperser to obtain a first dispersion liquid;

s5, dropwise adding a sodium hydroxide solution into the first dispersion liquid obtained in the S4, and adjusting the pH value of the first dispersion liquid to 4-5 to obtain a second dispersion liquid;

step S6, adding a silane coupling agent into the second dispersion liquid obtained in the step S5, ultrasonically dispersing for 1-2 hours by using an ultrasonic emulsification disperser, washing, filtering and drying to obtain a modified attapulgite/montmorillonite mixture;

and step S7, adding the cationic surfactant into deionized water, stirring and dissolving, then sequentially adding the modified attapulgite/montmorillonite mixture obtained in the step S6 and the thickening agent, stirring and dispersing for 30 minutes at the rotating speed of 3000 revolutions per minute, and adding a proper amount of defoaming agent for defoaming during stirring to obtain the pasty isolating agent.

In the embodiment, the attapulgite and the montmorillonite are compounded to be used as the main material of the separant. Attapulgite and montmorillonite can form high-viscosity suspension at relatively low concentration. In nature, attapulgite often coexists with montmorillonite, both of which have similar appearance and physical and chemical properties, cation exchangeability, water absorption, adsorption, thickening property, large specific surface area and colloid value, and in addition, both of which have chemical inertness, and the suspension of which is little affected by salt. Therefore, when the two are used as film separants for mixing or plasticating rubber and the like, the two have good adhesion with the film, can adsorb polar molecular substances permeating and migrating on the surface of the film, avoids adhesion between the films and improves the separation effect. In the subsequent processing process, the attapulgite and the montmorillonite are dispersed in the product as the filler, so that the mechanical property, the flame retardant property and the thermal stability of the rubber product can be improved. The nano-grade attapulgite and montmorillonite have more excellent comprehensive performance, but have poor dispersibility and are easy to agglomerate and settle as other nano materials.

The attapulgite is a non-metal mineral product with attapulgite as a main mineral component, and the attapulgite is a crystalline hydrated magnesium aluminum silicate mineral, and the basic structural unit of the attapulgite is a rod-shaped single crystal formed by two layers of silicon-oxygen tetrahedrons and one layer of magnesium (aluminum) oxygen octahedrons, which is called rod crystal for short. In the practical application state, when the microstructure is loose, the best effect of the rod crystal can be effectively exerted, and the macroscopic performance of the performance is good; on the other hand, when the microstructure is dense, the performance of the rod crystals is difficult to be exhibited, and the macroscopic expression of the performance is poor. Inside the attapulgite lattice, the basic structural units constituting the attapulgite are staggered to form nanometer size intracrystalline pores with partial octahedral cations (such as Na)⁺、Ca²⁺、Fe³⁺、Al³⁺And the like) are directly exposed on the surface of the pore channel, and the cations can be subjected to ion exchange with other cations, but the cation exchange capacity of the natural attapulgite is low, only 1/2-1/3 of montmorillonite is obtained, and the cation exchange capacity is increased along with the reduction of the particle size. If the cation exchange capacity is greatly improved, the modified cation exchange resin needs to be modified. The cation exchange capacity can be improved by adopting an acid modification method, and functional cations are introduced into the pore channels through cation exchange, so that the dispersion stability of the composite material is improved. Meanwhile, the acid modification can remove the impurity cement and carbonate minerals in the attapulgite, improve the specific surface area and dredge the pore channel. However, when acid modification is carried out, if the acid concentration used is high, the cations in the octahedral structure are almost completely dissolved, resulting in the loss of support of the tetrahedral structure and causing collapse.

Montmorillonite is a non-metal mineral product with montmorillonite as a main mineral component, and the montmorillonite structure is 2: type 1 crystal structure, a certain amount of cations (e.g. Ca) present in the layered structure formed by the montmorillonite unit cell²⁺、Mg²⁺、Al³⁺、Na⁺Etc.), these cations are easily exchanged with other cations, so that montmorillonite has more excellent cation exchange properties than attapulgite. In montmorillonite, the content of calcium-based montmorillonite is high but the comprehensive performance is not good enough, so that the montmorillonite is required to be modified by acidification to have higher dispersibility, water absorbability, adhesiveness, colloid performance and the like. The acid modification method of montmorillonite is mainly characterized by that it utilizes acids with different types and concentrations to soak montmorillonite so as to make Ca in the interlayer of montmorillonite be²⁺、Mg²⁺、Al³⁺The plasma metal ions are dissolved out in the form of soluble salt, so that the pore channel is dredged, the diffusion of adsorbate molecules is facilitated, and meanwhile, the radius of hydrogen atoms is less than that of Ca²⁺、Mg²⁺、Al³⁺So that H is ionized⁺Can replace metal cations between layers, thereby weakening the acting force between layers, leading the permanent negative charge on the montmorillonite belt to be more and being more beneficial to the exchange between cations.

In this embodiment, the attapulgite and the montmorillonite are ground to obtain nanoscale mixture particles, so that the comprehensive use performance of the mixture particles is improved, and then the surface of the mixture particles is modified so that the dispersibility of the mixture particles is improved. The modification path is plasma activation-acid modification-sodium salt modification-silane coupling agent modification. The four modification modes have synergistic effect, so that the modification effect is greatly improved, and the modified attapulgite/montmorillonite mixture with high dispersibility is obtained.

In the modification process, firstly, the attapulgite and the montmorillonite are activated by adopting an arc plasma method, and the Van der Waals force between the attapulgite and the montmorillonite and the bonding force of other ionic bonds are destroyed, so that the structure of the attapulgite and the montmorillonite becomes loose, and the comprehensive performance, the efficiency of subsequent process operation and the modification completion degree are greatly improved.

The activated attapulgite and montmorillonite are washed by water, soluble impurities and inorganic salts are removed preliminarily, and the purity of the attapulgite and montmorillonite is improved.

The plasma activated attapulgite and montmorillonite have loose structures, which is beneficial to ion exchange between cations, and the dilute hydrochloric acid solution is adopted for acidification modification, so that the collapse of a microstructure can be prevented, and the stability of the molecular structure of the attapulgite and montmorillonite is ensured. When the acidification is carried out, ultrasonic treatment is matched, so that the intermolecular motion frequency can be effectively improved, the cation exchange speed is enhanced, and the acidification modification efficiency and the acidification modification completion degree are improved.

And adjusting the pH value of the acidified and modified first dispersion liquid by adopting a sodium hydroxide solution. The sodium hydroxide solution reacts with the dilute hydrochloric acid to produce sodium chloride and water, so that the pH value in the modification process can be effectively controlled, the modification environment is kept to be weakly acidic, the generated sodium salt can be used for carrying out secondary modification on the attapulgite and the montmorillonite, and meanwhile, the weakly acidic environment is also beneficial to the subsequent modification of the silane coupling agent. Under the action of ultrasonic wave, the acidification modification, the sodium salt modification and the silane coupling agent modification are carried out synergistically, and the modification completion degree is further improved. The obtained modified attapulgite/montmorillonite mixture has excellent dispersibility and comprehensive performance.

The modified attapulgite/montmorillonite mixture is dispersed in the water solution containing the cationic surfactant, so that the dispersibility of the modified attapulgite/montmorillonite in water and the compatibility of the modified attapulgite/montmorillonite with the thickening agent can be further improved.

In some embodiments of the present invention, the concentration of the dilute hydrochloric acid solution in step S4 is 0.5 to 1 wt%; the concentration of the sodium hydroxide solution in the step S5 is 10-15 wt%.

In some embodiments of the present invention, when the ultrasonic emulsification disperser performs ultrasonic dispersion, the ultrasonic power is 200 to 500W, and the ultrasonic frequency is 20 to 25 kHz.

In some embodiments of the present invention, the silane coupling agent in step S6 is at least one of vinyltriethoxysilane, vinyltrimethoxysilane and vinyltris (β -methoxyethoxy) silane.

In some embodiments of the present invention, the cationic surfactant in step S7 is at least one of octadecyl trimethyl ammonium bromide, octadecyl trimethyl ammonium chloride, hexadecyl trimethyl ammonium bromide, and hexadecyl trimethyl ammonium chloride.

In some embodiments of the invention, the thickening agent in step S7 is sodium alginate. The sodium alginate has good thickening property and excellent salt tolerance, and is environment-friendly, pollution-free and high in use safety. Because the attapulgite and the montmorillonite also have excellent salt resistance, the viscosity loss of the attapulgite and the montmorillonite is small in a salt-containing environment, the process tolerance can be improved, and the using amount of the separant is reduced.

In some embodiments of the present invention, the attapulgite and the montmorillonite are mixed in the step S1 in a ratio of (2-8): 1 in a mass ratio;

in step S3, mixing the second mixture with the deionized water in a ratio of 1: (10-12) mixing in a mass ratio;

in step S4, mixing the third mixture with the dilute hydrochloric acid solution in a ratio of 1: (2-3) mixing in a mass ratio;

the silane coupling agent is added in an amount of 2.5 to 3.5wt% of the third mixture in step S3 in step S6;

in step S7, mixing the modified attapulgite/montmorillonite mixture, the cationic surfactant, the deionized water, and the thickener in a ratio of 100: (16-25): (500-650): (3-12) in a mass ratio.

Example 1

The embodiment provides a preparation method of a paste release agent, which comprises the following steps:

step S1, mixing attapulgite and montmorillonite in a mass ratio of 2:1, grinding the mixture in a grinder, and sieving the ground mixture to obtain a first mixture with the particle size of 200-800 nanometers;

s2, putting the first mixture obtained in the S1 into an arc plasma generator, and carrying out plasma treatment for 5-10 minutes under the direct-current voltage of 30-50 kV to obtain a second mixture;

step S3, mixing the second mixture obtained by step S2 in the ratio of 1: (10-12) adding the mixture into deionized water according to the mass ratio, stirring and dispersing, standing and precipitating, filtering out precipitates, repeatedly cleaning the precipitates for 3-5 times according to the operation, and drying to obtain a third mixture;

step S4, mixing the third mixture obtained by step S3 in the ratio of 1: (2-3) adding the mixture into a dilute hydrochloric acid solution with the concentration of 0.5-1 wt% according to the mass ratio, and performing ultrasonic dispersion for 1 hour at 70 +/-5 ℃ through an ultrasonic emulsion disperser under the conditions that the ultrasonic power is 200-500W and the ultrasonic frequency is 20-25 kHz to obtain a first dispersion liquid;

s5, dropwise adding a 10-15 wt% sodium hydroxide solution into the first dispersion liquid obtained in the step S4, and adjusting the pH value to 4-5 to obtain a second dispersion liquid;

step S6, adding vinyltriethoxysilane into the second dispersion liquid obtained in step S5 according to the amount of 2.5wt% of the third mixture, ultrasonically dispersing for 1-2 hours through an ultrasonic emulsification disperser under the conditions that the ultrasonic power is 200-500W and the ultrasonic frequency is 20-25 kHz, and washing, filtering and drying to obtain a modified attapulgite/montmorillonite mixture;

and step S7, adding 16 parts by mass of octadecyl trimethyl ammonium bromide into 580 parts by mass of deionized water, stirring and dissolving, then sequentially adding 100 parts by mass of the modified attapulgite/montmorillonite mixture obtained in the step S6 and 12 parts by mass of sodium alginate, stirring and dispersing for 30 minutes at the rotating speed of 3000 revolutions per minute, and adding a proper amount of defoaming agent for defoaming during stirring to obtain the pasty isolating agent.

Example 2

The embodiment provides a preparation method of a paste release agent, which comprises the following steps:

step S1, mixing attapulgite and montmorillonite according to a mass ratio of 8:1, grinding the mixture in a grinder, and sieving the ground mixture to obtain a first mixture with the particle size of 200-800 nanometers;

s2, putting the first mixture obtained in the S1 into an arc plasma generator, and carrying out plasma treatment for 5-10 minutes under the direct-current voltage of 30-50 kV to obtain a second mixture;

step S3, mixing the second mixture obtained by step S2 in the ratio of 1: (10-12) adding the mixture into deionized water according to the mass ratio, stirring and dispersing, standing and precipitating, filtering out precipitates, repeatedly cleaning the precipitates for 3-5 times according to the operation, and drying to obtain a third mixture;

step S4, mixing the third mixture obtained by step S3 in the ratio of 1: (2-3) adding the mixture into a dilute hydrochloric acid solution with the concentration of 0.5-1 wt% according to the mass ratio, and performing ultrasonic dispersion for 1 hour at 70 +/-5 ℃ through an ultrasonic emulsion disperser under the conditions that the ultrasonic power is 200-500W and the ultrasonic frequency is 20-25 kHz to obtain a first dispersion liquid;

s5, dropwise adding a 10-15 wt% sodium hydroxide solution into the first dispersion liquid obtained in the step S4, and adjusting the pH value to 4-5 to obtain a second dispersion liquid;

step S6, adding vinyltrimethoxysilane into the second dispersion liquid obtained in the step S5 according to the amount of 3.5wt% of the third mixture, performing ultrasonic dispersion for 1-2 hours by using an ultrasonic emulsion disperser under the conditions that the ultrasonic power is 200-500W and the ultrasonic frequency is 20-25 kHz, and washing, filtering and drying to obtain a modified attapulgite/montmorillonite mixture;

and step S7, adding 22 parts by mass of octadecyl trimethyl ammonium chloride into 500 parts by mass of deionized water, stirring and dissolving, then sequentially adding 100 parts by mass of the modified attapulgite/montmorillonite mixture obtained in the step S6 and 3 parts by mass of sodium alginate, stirring and dispersing for 30 minutes at the rotating speed of 3000 revolutions per minute, and adding a proper amount of defoaming agent for defoaming during stirring to obtain the pasty isolating agent.

Example 3

The embodiment provides a preparation method of a paste release agent, which comprises the following steps:

step S1, mixing attapulgite and montmorillonite according to a mass ratio of 5:1, grinding the mixture in a grinder, and sieving the ground mixture to obtain a first mixture with the particle size of 200-800 nanometers;

s2, putting the first mixture obtained in the S1 into an arc plasma generator, and carrying out plasma treatment for 5-10 minutes under the direct-current voltage of 30-50 kV to obtain a second mixture;

step S3, mixing the second mixture obtained by step S2 in the ratio of 1: (10-12) adding the mixture into deionized water according to the mass ratio, stirring and dispersing, standing and precipitating, filtering out precipitates, repeatedly cleaning the precipitates for 3-5 times according to the operation, and drying to obtain a third mixture;

step S4, mixing the third mixture obtained by step S3 in the ratio of 1: (2-3) adding the mixture into a dilute hydrochloric acid solution with the concentration of 0.5-1 wt% according to the mass ratio, and performing ultrasonic dispersion for 1 hour at 70 +/-5 ℃ through an ultrasonic emulsion disperser under the conditions that the ultrasonic power is 200-500W and the ultrasonic frequency is 20-25 kHz to obtain a first dispersion liquid;

s5, dropwise adding a 10-15 wt% sodium hydroxide solution into the first dispersion liquid obtained in the step S4, and adjusting the pH value to 4-5 to obtain a second dispersion liquid;

step S6, adding vinyltris (beta-methoxyethoxy) silane into the second dispersion liquid obtained in the step S5 according to the amount of 3wt% of the third mixture, performing ultrasonic dispersion for 1-2 hours by using an ultrasonic emulsification disperser under the conditions that the ultrasonic power is 200-500W and the ultrasonic frequency is 20-25 kHz, and washing, filtering and drying to obtain a modified attapulgite/montmorillonite mixture;

and S7, adding 25 parts by mass of hexadecyl trimethyl ammonium bromide into 650 parts by mass of deionized water, stirring and dissolving, then sequentially adding 100 parts by mass of the modified attapulgite/montmorillonite mixture obtained in the step S6 and 6 parts by mass of sodium alginate, stirring and dispersing for 30 minutes at the rotating speed of 3000 revolutions per minute, and adding a proper amount of defoaming agent for defoaming during stirring to obtain the pasty isolating agent.

Example 4

The embodiment provides a using method of a paste release agent, which comprises the following steps:

step S100, filling a pasty separant into a spherical first container 101, wherein the first container 101 is provided with small holes (not shown in the figure) with the diameter of 1-5 mm;

step S300, a cooling water tank 301 is divided into a water tank upper layer 303 and a water tank lower layer 304 through a detachable grating 302, a plurality of stirring devices 305 are arranged in the water tank lower layer 304, and the stirring devices 305 are respectively arranged at the bottom and the side wall of the water tank lower layer 304 and can be opened respectively or simultaneously;

step S500, placing one or more first containers 101 in the step S100 into the lower water tank layer 304 of the cooling water tank 301 in the step S300, wherein the first containers 101 float up and down along with the stirring of the stirring device 305, and the pasty isolating agent gradually releases from the small holes along with the floating of the first containers 101 and diffuses to the upper water tank layer 303;

step S700, immersing the film into the upper layer 303 of the water tank, coating the release agent, airing and stacking.

In this embodiment, the paste-like release agent is placed in the first container 101 having a spherical shape, which is more likely to float in water than other shapes. Through the floating of first container 101 in aqueous, the separant is released from the aperture, has realized the automation of paste adhesive and has diffused the dilution step by step, and convenient operation has avoided needing the workman to dilute the trouble that just can add the use after the adhesive segmentation manually in traditional operation.

By providing the stirring device 305 in the lower tank layer 304, the movement of the first container 101 can be promoted, and the dilution speed can be increased. By disposing the stirring devices 305 on the bottom and the side wall of the lower tank layer 304, respectively, a swirling flow can be formed in the lower tank layer 304 by alternately turning on the stirring devices 305 at different positions. The first container 101 is made to float rapidly in the lower layer 304 of the tank, and when there are a plurality of first containers 101, the dilution rate of the release agent can be further increased by the collision of the first containers 101 with each other.

The grill 302 both confines the first container 101 within the lower basin 304 and has a flow stabilizing effect that facilitates the wetting of the film within the upper basin 303.

The release agent has excellent thixotropy, so the release agent has low viscosity and good fluidity under the stirring condition, is convenient to quickly coat on the surface of a film, and after the film is taken out from the cooling water tank 301, the viscosity of the release agent is quickly increased under the condition of losing shearing force, so the adhesive force of the release agent on the surface of the film is improved, and the sagging phenomenon is effectively prevented.

Example 5

The embodiment provides another using method of the pasty release agent, which comprises the following steps:

step S200, filling the pasty isolating agent into a second container 201 with an opening at one end, wherein a cover body 202 is arranged at the opening of the second container 201, and small holes (not shown in the figure) with the diameter of 1-5 mm are respectively formed in the side wall of the second container 201 and the cover body 202;

step S400, a cooling water tank 301 is divided into an upper water tank layer 303 and a lower water tank layer 304 through a detachable grid 302, and a rotating disc 401 capable of horizontally rotating is arranged at the bottom of the lower water tank layer 304;

step S600, fixing one or more second containers 201 in the step S200 on the rotating disc 401 in the cooling water tank 301 in the step S400, and gradually dissolving and diluting the pasty isolating agent from the small holes along with the rotation of the rotating disc 401 and diffusing the pasty isolating agent to the upper layer 303 of the water tank;

step S800, immersing the film into the upper layer 303 of the water tank, coating the isolating agent, airing and stacking.

In this embodiment, the rotary plate 401 is provided at the bottom of the lower tank layer 304 of the cooling water tank 301, and the second container 201 is fixed to the rotary plate 401, so that the dilution rate of the partitioning agent can be controlled by adjusting the rotation speed of the rotary plate 401. The small hole on the side wall of the second container 201 and the small hole on the cover 202 can form an upward flow channel, during the rotation process, the water pressure born by the side wall of the second container 201 is larger than that born by the cover 202, so that the pasty isolating agent is diluted and released from the small hole on the side wall of the second container 201, simultaneously, water enters the second container 201 from the side wall and flows to the cover 202 with low pressure, the pasty isolating agent in the second container 201 is squeezed towards the cover 202, and is enabled to simultaneously flow out from the small hole on the cover 202, and the dilution speed of the adhesive is improved. Meanwhile, the rotating disc 401 and the second container 201 together form a stirring structure, and the stirring operation of the liquid in the cooling water tank 301 is realized.

Comparative example 1

This comparative example prepared a paste-like release agent, which was the one excluding the arc plasma activation operation of step S2, on the basis of example 3.

Comparative example 2

The comparative example provides a paste separant, which is prepared by removing montmorillonite on the basis of example 3 and only adopting attapulgite as a main raw material.

Isolation effect detection:

stirring and diluting the paste-shaped release agent in the examples 1-3 and the comparative examples 1-2 with water according to the proportion of 1:20 to obtain a release agent solution, immersing two pieces of 300mmX300mmX3mm plasticated natural rubber sheets into the release agent solution under the stirring state, taking out after 5 seconds, airing, stacking, and placing 1000g of steel plates for pressing. The blocking was observed at room temperature and the results are shown in Table 1:

the above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents and are included in the scope of the present invention.