Opening agent as well as preparation method and application thereof

Abstract

The invention relates to the field of synthetic resin, in particular to an anti-blocking agent as well as a preparation method and application thereof. The method comprises the following steps: (1) carrying out wet ball milling on the gasified slag, and then carrying out first filtering, first drying and first crushing to obtain pretreated slag; (2) in an oxygen-containing atmosphere, carrying out first calcination on the pretreated slag, and then carrying out second crushing to obtain an intermediate material; (3) carrying out a hydrothermal reaction on the intermediate material and a sodium hydroxide solution, and then carrying out second filtration to obtain a filtrate; and (4) adjusting the pH value of the filtrate to 6-8 by using inorganic acid, then aging, and then sequentially carrying out third filtration, washing, drying and second calcination. According to the method, coal chemical gasification filter cake fine slag is used as a raw material, resource utilization of solid waste is achieved, and the method has the advantages of being wide in raw material source, low in price and simple in preparation process.

Description

Technical Field

[0001] This invention relates to the field of synthetic resins, and more specifically to an opening agent, its preparation method, and its application. Background Technology

[0002] Novel polypropylene film materials have received increasing attention in recent years due to their excellent performance and broad application prospects. Based on production processes and application areas, they are mainly classified into several types, such as uniaxially oriented polypropylene (BOPP) film, biaxially oriented polypropylene (BOPP) film, and multilayer co-extruded film. During the production process of polypropylene film, auxiliary materials such as antioxidants, UV stabilizers, plasticizers, and colorants are typically added to improve film performance, broaden application areas, and enhance product value. Polypropylene film opening agents are key additives in film materials, improving opening performance, reducing the coefficient of friction, preventing adhesion between film layers, and enhancing tensile strength and other properties.

[0003] Polypropylene film opening agents have gone through three generations of products: the first generation includes talc, diatomaceous earth, and dicalcium phosphate, which have the disadvantage of poor opening performance and affect the optical and other physicochemical properties of the plastic film; the second generation includes oleamide, erucamide, and ethylene bis-stearamide (EBS) derivatives, which have the disadvantage of organic opening agent precipitates adhering to the film surface, affecting the film's printability, heat-sealing properties, and color, and also affecting its safety as a food packaging material; the third generation is silica, which has the advantages of good opening performance and non-toxicity, and is currently the most widely used.

[0004] Currently, the main synthesis process for third-generation plastic film opening agents uses sodium silicate water glass as the silicon source. For example, the preparation method disclosed in patent application CN116004036A includes: forming a silica sol by pressurized convection of a water glass solution and sulfuric acid; heating to adjust the pH to alkaline; adding a silane coupling agent for modification; after aging, adjusting the pH to acidic; aging to form a silica gel; washing; uniform dispersion after washing; drying; and finally pulverizing to obtain the opening agent. The film opening agent particles prepared by this method are uniform and easily dispersed, exhibiting good transparency and processing performance in the production of polyethylene terephthalate plastic films. Patent application CN115873342A incorporates micron-sized solid glass microspheres and talc powder as mineral powder. The layered structure of talc powder can improve the stiffness of the film, while the solid glass microspheres can form protrusions on the film surface, thus acting as openings. Simultaneously, during the mixing process, the solid glass microspheres can break down the multi-layered structure of talc powder into a single-layered structure through mechanical collision, promoting the wetting of the coupling agent and talc powder, and promoting the uniform dispersion of the single-layered structure of talc powder in the material, thereby improving the transparency of the film. Summary of the Invention

[0005] The purpose of this invention is to address the problems existing in the prior art by providing an opening agent, its preparation method, and its application.

[0006] To achieve the above objectives, the present invention provides a method for preparing an opening agent, the method comprising the following steps:

[0007] (1) The gasification residue is subjected to wet ball milling, followed by first filtration, first drying and first pulverization to obtain pretreated residue;

[0008] (2) In an oxygen-containing atmosphere, the pretreated slag is first calcined and then second crushed to obtain intermediate material;

[0009] (3) The intermediate material and sodium hydroxide solution are subjected to a hydrothermal reaction, and then a second filtration is performed to obtain the filtrate;

[0010] (4) Adjust the pH of the filtrate to 6-8 using an inorganic acid, then age it, and then perform a third filtration, washing, drying and second calcination in sequence;

[0011] The gasification slag is a dry base of fine residue from coal chemical gasification filter cake, and the particle size of the gasification slag is 1-150 μm.

[0012] The gasification slag contains 5-20 wt% residual carbon and 40-60 wt% silicon dioxide.

[0013] Preferably, in step (1), the solvent used in the wet ball milling is water; and / or,

[0014] Preferably, the solid-liquid ratio of the gasification slag to the water is 100-500 g / L; and / or,

[0015] The first drying conditions include: a temperature of 100-150°C and a time of 1-4 hours; and / or,

[0016] Preferably, the particle size of the pretreated residue is 1-50 μm.

[0017] Preferably, the conditions for the first calcination include: a temperature of 600-1000℃ and a time of 3-8h.

[0018] Preferably, the weight ratio of the intermediate material to the sodium hydroxide in the sodium hydroxide solution is 1:1.5-2.5; and / or,

[0019] The concentration of the sodium hydroxide solution is 10-30 wt%; and / or,

[0020] The conditions for the hydrothermal reaction include: a temperature of 150-250℃ and a time of 2-6 hours.

[0021] Preferably, the inorganic acid includes sulfuric acid and / or hydrochloric acid; and / or,

[0022] The aging time is 1-3 hours; and / or,

[0023] The conditions for the second calcination include: a temperature of 700-800℃ and a time of 2-6 hours.

[0024] A second aspect of the present invention provides an opening agent prepared by the method described above.

[0025] A third aspect of the present invention provides a polypropylene composition comprising a terpolymer polypropylene, an opening agent, an antioxidant, an acid absorber, and a slip agent;

[0026] The opening agent is the opening agent described above.

[0027] Preferably, the melt flow index of the terpolymer polypropylene is 7-9 g / 10 min; and / or,

[0028] Relative to 100 parts by weight of ternary copolymer polypropylene, the amount of the opening agent is 0.05-0.2 parts by weight, the amount of the antioxidant is 0.3-0.8 parts by weight, the amount of the acid absorbent is 0.03-0.05 parts by weight, and the amount of the slip agent is 0.05-0.2 parts by weight.

[0029] A fourth aspect of the present invention provides a polypropylene film material, which is obtained by melt blending and extrusion granulation of the composition described above.

[0030] The fifth aspect of the present invention provides a polypropylene film, which is obtained by casting the polypropylene film material described above.

[0031] Compared with related technologies, the present invention has the following beneficial effects:

[0032] This invention provides a method for preparing an opening agent. This method utilizes fine residue from coal chemical gasification filter cake as raw material, achieving resource utilization of solid waste. It has the advantages of wide availability of raw materials, low price, and simple preparation process. Furthermore, using the prepared opening agent in the preparation of polypropylene films is beneficial for obtaining film materials with high transparency, good opening performance, good tensile properties, and good anti-blocking properties. Attached Figure Description

[0033] Figure 1 These are scanning electron microscope images of the opening agent prepared in Example 2;

[0034] Figure 2 This is a scanning electron microscope image of the polypropylene film material prepared in Example 2. Detailed Implementation

[0035] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0036] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0037] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions provided in the various embodiments of this invention can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0038] Coal gasification filter cake residue is a solid waste generated during the coal chemical production process. It is produced from black wastewater generated by coal gasification units after flocculation, sedimentation, filtration, and dewatering. It is characterized by high water content, fine particles, large particle specific surface area, high residual carbon content, and abundant silicon oxides. This waste has emerged with the rise of new coal chemical industries, and its treatment is becoming increasingly urgent. Based on this, the inventors of this invention have creatively proposed a method for preparing an initiating agent using coal gasification filter cake residue.

[0039] This invention provides a method for preparing an opening agent, the method comprising the following steps:

[0040] (1) The gasification residue is subjected to wet ball milling, followed by first filtration, first drying and first pulverization to obtain pretreated residue;

[0041] (2) In an oxygen-containing atmosphere, the pretreated slag is first calcined and then second crushed to obtain intermediate material;

[0042] (3) The intermediate material and sodium hydroxide solution are subjected to a hydrothermal reaction, and then a second filtration is performed to obtain the filtrate;

[0043] (4) Adjust the pH of the filtrate to 6-8 using an inorganic acid, then age it, and then perform a third filtration, washing, drying and second calcination in sequence;

[0044] The gasification slag is a dry base of fine residue from coal chemical gasification filter cake, and the particle size of the gasification slag is 1-150 μm.

[0045] The gasification slag contains 5-20 wt% residual carbon and 40-60 wt% silicon dioxide.

[0046] In this invention, the dry basis of the coal chemical gasification filter cake is obtained by drying the fine residue of the coal chemical gasification filter cake, and the moisture content of the dry basis of the coal chemical gasification filter cake is usually ≤0.1wt%.

[0047] In some specific embodiments, the particle size of the gasification slag can be 1μm, 5μm, 10μm, 20μm, 50μm, 75μm, 100μm, 125μm, 150μm, or any two of these point values ​​as end values ​​within a range.

[0048] In some specific embodiments, the residual carbon content of the gasification slag can be 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, 20 wt%, or any two of these point values ​​as endpoints.

[0049] In some specific embodiments, the silica content of the gasification slag can be 40wt%, 42wt%, 45wt%, 48wt%, 50wt%, 52wt%, 55wt%, 58wt%, 60wt%, or any two of these point values ​​as end values ​​within a range.

[0050] In some preferred embodiments, the solvent used in step (1) for wet ball milling is water. More preferably, the solid-liquid ratio of the gasified slag to water used in wet ball milling can be 100-500 g / L. As examples, it can be 100 g / L, 150 g / L, 200 g / L, 250 g / L, 300 g / L, 350 g / L, 400 g / L, 450 g / L, or 500 g / L.

[0051] In some specific embodiments, the wet ball milling time can be 0.5 hours.

[0052] According to the present invention, there are no special requirements for the first filtration method, and conventional methods in the art can be used, such as vacuum filtration.

[0053] In some preferred embodiments, the conditions for the first drying include a temperature of 100-150°C and a time of 1-4 hours. As an example, the temperature for the first drying can be 100°C, 105°C, 110°C, 115°C, 120°C, 125°C, 130°C, 135°C, 140°C, 145°C, or 150°C.

[0054] In some preferred embodiments, the particle size of the pretreated residue is controlled to be 1-50 μm after the first crushing.

[0055] In the method described in this invention, in step (2), the oxygen-containing atmosphere can be provided by air or oxygen.

[0056] In some preferred embodiments, the conditions for the first calcination include a temperature of 600-1000°C and a time of 3-8 hours. As an example, the temperature of the first calcination can be 600°C, 700°C, 800°C, 900°C, or 1000°C, and the time of the first calcination can be 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, or 8 hours.

[0057] In some preferred embodiments, the weight ratio of the intermediate material to the sodium hydroxide in the sodium hydroxide solution is 1:1.5-2.5.

[0058] More preferably, the concentration of the sodium hydroxide solution is 10-30 wt%.

[0059] In some preferred embodiments, the conditions for the hydrothermal reaction include a temperature of 150-250°C and a time of 2-6 hours. For example, the temperature of the hydrothermal reaction can be 150°C, 160°C, 170°C, 180°C, 190°C, 200°C, 210°C, 220°C, 230°C, 240°C, or 250°C, and the reaction time can be 2 hours, 3 hours, 4 hours, 5 hours, or 6 hours.

[0060] In some preferred embodiments, the specific process of step (4) includes: heating the filtrate obtained in step (3) to 70-90°C, then adding an inorganic acid solution dropwise until the pH of the system is 6-8, then aging, and then sequentially performing third filtration, washing, drying and second calcination.

[0061] In some preferred embodiments, the inorganic acid includes sulfuric acid and / or hydrochloric acid.

[0062] In some preferred embodiments, the aging time is 1-3 hours.

[0063] In some preferred embodiments, the conditions for the second calcination include: a temperature of 700-800°C and a time of 2-6 hours.

[0064] A second aspect of the present invention provides an opening agent prepared by the method described above.

[0065] A third aspect of the present invention provides a polypropylene composition comprising a terpolymer polypropylene, an opening agent, an antioxidant, an acid absorber, and a slip agent;

[0066] The opening agent is the opening agent described above.

[0067] Understandably, in this invention, the ternary copolymer polypropylene is a polymer obtained by random copolymerization of ethylene, propylene and butene.

[0068] In some specific embodiments, the melt index of the ternary copolymer polypropylene is 7-9 g / 10 min.

[0069] In some preferred embodiments, the content of the opening agent is 0.05-0.2 parts by weight, the content of the antioxidant is 0.3-0.8 parts by weight, the content of the acid absorber is 0.03-0.05 parts by weight, and the content of the slip agent is 0.05-0.2 parts by weight, relative to 100 parts by weight of ternary copolymer polypropylene.

[0070] As an example, the content of the opening agent relative to 100 parts by weight of ternary copolymer polypropylene can be 0.05 parts by weight, 0.1 parts by weight, 0.15 parts by weight, or 0.2 parts by weight.

[0071] As an example, the antioxidant content may be 0.3 parts by weight, 0.4 parts by weight, 0.5 parts by weight, 0.6 parts by weight, 0.7 parts by weight, or 0.8 parts by weight relative to 100 parts by weight of ternary copolymer polypropylene.

[0072] As an example, the content of acid scavenger relative to 100 parts by weight of ternary copolymer polypropylene can be 0.03 parts by weight, 0.04 parts by weight, or 0.05 parts by weight.

[0073] As an example, the content of the slip agent relative to 100 parts by weight of ternary copolymer polypropylene can be 0.05 parts by weight, 0.1 parts by weight, 0.15 parts by weight, or 0.2 parts by weight.

[0074] In some preferred embodiments, the antioxidant includes a primary antioxidant and a secondary antioxidant.

[0075] In a preferred embodiment, the primary antioxidant is selected from hindered phenolic antioxidants or thioester antioxidants. More preferably, it is at least one of BASF 1010 (pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]), BASF 3114 (1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanuric acid), and BASF 245 ([β-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate)).

[0076] In a preferred embodiment, the auxiliary antioxidant is a phosphite antioxidant or an ester antioxidant. More preferably, it is AP-618 (pentaerythritol dioctadecanyl phosphite).

[0077] In some specific embodiments, the antioxidant is a compound antioxidant of BASF 1010 and AP-168, and the weight ratio of BASF 1010 and AP-168 is 1:2.

[0078] In some preferred embodiments, the acid absorber is at least one selected from calcium stearate, zinc stearate, and hydrotalcite, preferably calcium stearate. Understandably, the acid absorber is primarily used to absorb and eliminate residual catalyst in the polypropylene.

[0079] In some preferred embodiments, the slip agent is at least one selected from erucamide, oleamide, silicone-based slip agents, and polyethylene wax, more preferably erucamide. Understandably, the slip agent is primarily used to improve the surface smoothness and anti-blocking effect of polypropylene materials.

[0080] A fourth aspect of the present invention provides a polypropylene film material, which is obtained by melt blending and extrusion granulation of the composition described above.

[0081] Understandably, there are no special requirements for the conditions of melt blending and extrusion granulation, and they can be carried out under conditions conventional in the art. For example, a twin-screw extruder can be used for melt blending and extrusion granulation.

[0082] The fifth aspect of the present invention provides a polypropylene film, which is obtained by casting the polypropylene film material described above.

[0083] Understandably, there are no special requirements for the conditions and methods of casting; conventional conditions and methods in this field can be used. For example, the polypropylene material described above can be made into a polypropylene film using a casting film machine.

[0084] To make the objectives and advantages of the present invention clearer, the preparation method and effects of the opening agent of the present invention are further described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are only for explaining the present invention and should not be used to limit the present invention. Unless otherwise specified, the following embodiments do not include components other than unavoidable impurities. Unless otherwise specified, the drugs and instruments used in the embodiments are conventionally selected in the art. Experimental methods in the embodiments that do not specify specific conditions are implemented according to conventional conditions, such as those described in literature, books, or methods recommended by the manufacturer.

[0085] Example 1

[0086] Preparation of opening agent S1:

[0087] (1) Weigh a certain amount of gasification slag (coal chemical gasification filter cake fine residue dry basis, particle size 5-100μm, residual carbon content 10wt%, silicon dioxide content 50wt%) and distilled water to prepare a slurry. The solid-liquid ratio of gasification slag to distilled water is 250g / L. Use a planetary ball mill to mechanically crush the slurry for 4 hours. Use a vacuum filter to filter the gasification slag slurry. Take the filter cake and dry it at 120℃ for 3 hours. Then cool it to 20℃. Use a crusher to crush the dried and agglomerated gasification slag for 5 minutes until the particle size is 2-10μm to obtain pretreated slag.

[0088] (2) The pretreated slag was placed in a high-temperature muffle furnace and calcined at 800°C under aerobic conditions for 4 hours. After naturally cooling to 20°C, it was crushed again for 30 minutes to obtain powder to obtain intermediate material.

[0089] (3) Weigh a certain amount of intermediate material and put it into a high-pressure reactor and add a sodium hydroxide solution with a concentration of 15wt%. Control the weight ratio of intermediate material to sodium hydroxide to be 1:1.5. Then, perform hydrothermal reaction at 200℃ for 5 hours. After natural cooling, perform vacuum filtration and wash the filter cake with distilled water 5 times. Collect the filtrate.

[0090] (4) Heat the filtrate to 85°C. After the temperature stabilizes, slowly add sulfuric acid with a concentration of 64.3wt%. Stop adding the solution when the pH drops to 7. Then age it for 1.5 hours. Next, filter it and wash it three times with distilled water. Take the filter cake and vacuum dry it for 2 hours. Grind the dried filter cake into powder and place it in a high-temperature muffle furnace. Calcine it at 750°C for 4 hours to obtain the opening agent S1.

[0091] Preparation of polypropylene film:

[0092] The polypropylene composition comprises: 100 parts by weight of ternary copolymer polypropylene powder (FC5608 powder from the Olefins Division II of Ningxia Coal Industry Co., Ltd., State Energy Group), 0.3 parts by weight of compounded antioxidant (BASF 1010 and AP-168 compounded in a weight ratio of 1:2), 0.04 parts by weight of acid scavenger (DHT-4A), 0.05 parts by weight of slip agent (erucamide), and 0.2 parts by weight of opening agent S1;

[0093] The above composition is mixed evenly and extruded and granulated using a twin-screw extruder to obtain polypropylene film material granules; then, the polypropylene film material granules are processed by a casting film machine to obtain a polypropylene film with a thickness of 30 micrometers.

[0094] Example 2

[0095] Preparation of opening agent S2:

[0096] (1) Weigh a certain amount of gasification slag (coal chemical gasification filter cake fine residue dry basis, particle size 10-90μm, residual carbon content 15wt%, silicon dioxide content 50wt%) and distilled water to prepare a slurry. The solid-liquid ratio of gasification slag to distilled water is 250g / L. Use a planetary ball mill to mechanically crush the gasification slag slurry for 1 hour. Use a vacuum filter to filter the gasification slag slurry. Take the filter cake and dry it at 120℃ for 3 hours. Then cool it to 20℃. Use a crusher to crush the dried and agglomerated gasification slag for 5 minutes until the particle size is 2-15μm to obtain pretreated slag.

[0097] (2) The pretreated slag is then placed in a high-temperature muffle furnace and calcined at 800°C under aerobic conditions for 4 hours. After naturally cooling to 20°C, it is crushed again for 30 minutes to obtain powder to obtain intermediate material.

[0098] (3) Weigh a certain amount of intermediate material, put it into a high-pressure reactor, and add a sodium hydroxide solution with a concentration of 15wt%. Control the weight ratio of intermediate material to gasification slag to sodium hydroxide to be 1:2. Then, perform hydrothermal reaction at 200℃ for 5 hours. After natural cooling, perform vacuum filtration and wash the filter cake with distilled water 5 times. Collect the filtrate.

[0099] (4) Heat the filtrate to 85°C. After the temperature stabilizes, slowly add sulfuric acid with a concentration of 64.3wt%. Stop adding the solution when the pH drops to 7. Then, age it for 1.5 hours and filter it. Wash it three times with distilled water. Take the filter cake and vacuum dry it for 2 hours. Grind the dried filter cake into powder and place it in a high-temperature muffle furnace. Calcine it at 750°C for 4 hours to obtain the opening agent S2.

[0100] Figure 1 The above-mentioned opening agent is shown in a scanning electron microscope image, combined with... Figure 1It can be seen that the opening agent has an irregular amorphous structure with dimensions all below 20 μm.

[0101] Preparation of polypropylene film:

[0102] The polypropylene composition comprises: 100 parts by weight of ternary copolymer polypropylene powder (same as in Example 1), 0.3 parts by weight of compounded antioxidant (same as in Example 1), 0.04 parts by weight of acid absorbent (same as in Example 1), 0.05 parts by weight of slip agent (same as in Example 1), and 0.18 parts by weight of opening agent S2.

[0103] The above composition was mixed evenly and then extruded and granulated using a twin-screw extruder to obtain polypropylene film material granules; a scanning electron microscope image of the polypropylene film material is shown below. Figure 2 As shown, the opening agent is well embedded in the polypropylene film material; then the above polypropylene film material particles are processed by a casting film machine to obtain a polypropylene film with a thickness of 30 micrometers.

[0104] Example 3

[0105] Preparation of opening agent S3:

[0106] (1) Weigh a certain amount of gasification slag (coal chemical gasification filter cake fine slag dry basis, particle size 5-100μm, residual carbon content 10wt%, silicon dioxide content 50wt%) and distilled water to prepare a slurry. The solid-liquid ratio of gasification slag to distilled water is 250g / L. Use a planetary ball mill to mechanically crush the gasification slag slurry for 0.5h. Use a vacuum filter to filter the gasification slag slurry. Take the filter cake and dry it at 120℃ for 3 hours. Then cool it to 20℃. Use a crusher to crush the dried and agglomerated gasification slag for 5 minutes until the particle size is 2-20μm to obtain pretreated slag.

[0107] (2) The pretreated slag is then placed in a high-temperature muffle furnace and calcined at 800°C under aerobic conditions for 4 hours. After naturally cooling to 20°C, it is crushed again for 30 minutes to obtain powder to obtain intermediate material.

[0108] (3) Weigh a certain amount of intermediate material, put it into a high-pressure reactor, and add a sodium hydroxide solution with a concentration of 15wt%. Control the weight ratio of intermediate material to gasification slag to sodium hydroxide to be 1:2.2. Then, perform hydrothermal reaction at 200℃ for 5 hours. After natural cooling, perform vacuum filtration and wash the filter cake 5 times with distilled water. Collect the filtrate.

[0109] (4) Heat the filtrate to 85°C. After the temperature stabilizes, slowly add sulfuric acid with a concentration of 64.3wt%. Stop adding the solution when the pH drops to 7. Then, age it for 1.5 hours and filter it. Wash it three times with distilled water. Take the filter cake and vacuum dry it for 2 hours. Grind the dried filter cake into powder and place it in a high-temperature muffle furnace. Calcine it at 750°C for 4 hours to obtain the opening agent S3.

[0110] Preparation of polypropylene film:

[0111] The polypropylene composition comprises: 100 parts by weight of ternary copolymer polypropylene powder (same as in Example 1), 0.3 parts by weight of compounded antioxidant (same as in Example 1), 0.04 parts by weight of acid absorbent (same as in Example 1), 0.05 parts by weight of slip agent (same as in Example 1), and 0.18 parts by weight of opening agent S3;

[0112] The above composition is mixed evenly and extruded and granulated using a twin-screw extruder to obtain polypropylene film material granules; then, the polypropylene film material granules are processed by a casting film machine to obtain a polypropylene film with a thickness of 30 micrometers.

[0113] Example 4

[0114] Preparation of opening agent S4:

[0115] (1) Weigh a certain amount of gasification slag (coal chemical gasification filter cake fine residue dry basis, particle size 5-100μm, residual carbon content 10wt%, silicon dioxide content 50wt%) and distilled water to prepare a slurry. The solid-liquid ratio of gasification slag to distilled water is 250g / L. Use a planetary ball mill to mechanically crush the gasification slag slurry for 0.5h. Use a vacuum filter to filter the gasification slag slurry. Take the filter cake and dry it at 120℃ for 3 hours. Then cool it to 20℃. Use a crusher to crush the dried and agglomerated gasification slag for 5 minutes until the particle size is 2-30μm to obtain pretreated slag.

[0116] (2) The pretreated slag is then placed in a high-temperature muffle furnace and calcined at 800°C under aerobic conditions for 4 hours. After naturally cooling to 20°C, it is crushed again for 20 minutes to obtain powder to obtain intermediate material.

[0117] (3) Weigh a certain amount of intermediate material, put it into a high-pressure reactor, and add a sodium hydroxide solution with a concentration of 15wt%. Control the weight ratio of intermediate material to gasification slag to sodium hydroxide to be 1:2.5. Then, perform hydrothermal reaction at 200℃ for 5 hours. After natural cooling, perform vacuum filtration and wash the filter cake 5 times with distilled water. Collect the filtrate.

[0118] (4) Heat the filtrate to 85°C. After the temperature stabilizes, slowly add sulfuric acid with a concentration of 64.3 wt%. Stop adding the solution when the pH drops to 7. Then, age it for 1.5 hours and filter it. Wash it three times with distilled water. Take the filter cake and vacuum dry it for 2 hours. Grind the dried filter cake into powder and place it in a high-temperature muffle furnace. Calcine it at 750°C for 4 hours to obtain the opening agent S4.

[0119] Preparation of polypropylene film:

[0120] The polypropylene composition comprises: 100 parts by weight of ternary copolymer polypropylene powder (same as in Example 1), 0.3 parts by weight of compounded antioxidant (same as in Example 1), 0.04 parts by weight of acid absorber (same as in Example 1), 0.05 parts by weight of slip agent (same as in Example 1), and 0.18 parts by weight of opening agent S4.

[0121] The above composition is mixed evenly and extruded and granulated using a twin-screw extruder to obtain polypropylene film material granules; then, the polypropylene film material granules are processed by a casting film machine to obtain a polypropylene film with a thickness of 30 micrometers.

[0122] Comparative Example 1

[0123] The polypropylene composition comprises: 100 parts by weight of ternary copolymer polypropylene powder (same as in Example 1), 0.3 parts by weight of compounded antioxidant (same as in Example 1), 0.04 parts by weight of acid absorber (same as in Example 1), 0.05 parts by weight of slip agent (same as in Example 1), and 0.2 parts by weight of opening agent (commercially available opening agent AB905).

[0124] The above composition is mixed evenly and extruded and granulated using a twin-screw extruder to obtain polypropylene film material granules; then, the polypropylene film material granules are processed by a casting film machine to obtain a polypropylene film with a thickness of 30 micrometers.

[0125] Test case

[0126] The properties of the films prepared in the examples and comparative examples were tested:

[0127] The melt flow index was measured according to GB / T 3682-2000 standard;

[0128] Bending performance was measured according to GB / T 934l-2008 standard;

[0129] The notched impact strength of the simply supported beam was measured according to GB / T 1043.1-2008 standard; the tensile properties were measured according to GB / T1040.2-2006 standard.

[0130] The Vicat softening temperature was measured according to GB / T 1634-2019 standard, and the light transmittance / haze was measured according to GB / T 2410-2008 standard; the dynamic / static friction coefficients of the film were measured according to GB / T 10006-2021 standard. The test results are shown in Tables 1 and 2.

[0131] Table 1

[0132]

[0133] Table 2

[0134]

[0135]

[0136] As shown in Tables 1 and 2, the opening agent preparation method provided by this invention utilizes fine residue from coal chemical gasification filter cake as raw material, which not only realizes the resource utilization of solid waste but also produces an opening agent with excellent performance. When this opening agent is used in the preparation of polypropylene films, film materials with high transparency, good opening performance, good tensile properties, and good anti-blocking properties can be obtained.

[0137] It should be understood that any parts not described in detail in this specification belong to the prior art.

[0138] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for preparing an opening agent, characterized in that, The method includes the following steps: (1) The gasification residue is subjected to wet ball milling, followed by first filtration, first drying and first pulverization to obtain pretreated residue; (2) In an oxygen-containing atmosphere, the pretreated slag is first calcined and then second crushed to obtain intermediate material; (3) The intermediate material and sodium hydroxide solution are subjected to a hydrothermal reaction, and then a second filtration is performed to obtain the filtrate; (4) Adjust the pH of the filtrate to 6-8 using an inorganic acid, then age it, and then perform a third filtration, washing, drying and second calcination in sequence; The gasification slag is a dry base of fine residue from coal chemical gasification filter cake, and the particle size of the gasification slag is 1-150 μm. The gasification slag contains 5-20 wt% residual carbon and 40-60 wt% silicon dioxide.

2. The method according to claim 1, characterized in that, In step (1), the solvent used in the wet ball milling is water; and / or, The solid-liquid ratio of the gasification residue to the water is 100-500 g / L; and / or The first drying conditions include: a temperature of 100-150°C and a time of 1-4 hours; and / or The particle size of the pretreated residue is 1-50 μm.

3. The method according to claim 1 or 2, characterized in that, The conditions for the first calcination include: a temperature of 600-1000℃ and a time of 3-8 hours.

4. The method according to claim 1 or 2, characterized in that, The weight ratio of the intermediate material to the sodium hydroxide in the sodium hydroxide solution is 1:1.5-2.5; And / or, The concentration of the sodium hydroxide solution is 10-30 wt%. And / or, The conditions for the hydrothermal reaction include: a temperature of 150-250℃ and a time of 2-6 hours.

5. The method according to claim 1 or 2, characterized in that, The inorganic acid includes sulfuric acid and / or hydrochloric acid; and / or, The aging time is 1-3 hours; And / or, The conditions for the second calcination include: a temperature of 700-800℃ and a time of 2-6 hours.

6. An opening agent, characterized in that, It is prepared by the method described in any one of claims 1-5.

7. A polypropylene composition, characterized in that, The composition comprises ternary copolymer polypropylene, an opening agent, an antioxidant, an acid absorber, and a slip agent; The opening agent is the opening agent according to claim 6.

8. The composition according to claim 7, characterized in that, The melt flow index of the ternary copolymer polypropylene is 7-9 g / 10 min; and / or, Relative to 100 parts by weight of ternary copolymer polypropylene, the amount of the opening agent is 0.05-0.2 parts by weight, the amount of the antioxidant is 0.3-0.8 parts by weight, the amount of the acid absorbent is 0.03-0.05 parts by weight, and the amount of the slip agent is 0.05-0.2 parts by weight.

9. A polypropylene film material, characterized in that, The composition of claim 7 or 8 is obtained by melt blending and extrusion granulation.

10. A polypropylene film, characterized in that, The polypropylene film is obtained by casting the polypropylene film material according to claim 9.

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