Screw cleaning material, method for producing the same, and method for cleaning a screw of a processing apparatus

Abstract

The application discloses a screw cleaning material, and raw materials of the screw cleaning material include, in parts by weight, 50-60 parts of a base resin, 30-45 parts of modified inorganic fillers, 1-5 parts of a surfactant, 0.5-5 parts of a compatilizer, and 0.2-3 parts of an antioxidant; the modified inorganic fillers are inorganic fillers modified by an alcohol compound and a silane coupling agent. The base resin, the modified inorganic fillers, the surfactant, the compatilizer and the antioxidant are compounded, the modified inorganic fillers can be more uniformly dispersed in the resin matrix, meanwhile, through mutual cooperation between physical friction and chemical action of the components, dirt on the surface of the screw can be efficiently and thoroughly removed, and meanwhile, the screw is not damaged. The application further discloses a preparation method of the screw cleaning material and a screw cleaning method of a processing equipment.

Description

Technical Field

[0001] The present invention relates to the technical field of composite polymer materials, in particular to a screw cleaning material and a preparation method thereof, and a screw cleaning method for processing equipment. Background Art

[0002] During the processing of plastic products, processing equipment such as extruders often accumulates raw materials to varying degrees. This leads to material waste and environmental pollution during operations such as color and material changes. For example, pigment residue in the screw can cause significant color deviation and result in substandard products. Therefore, cleaning these processing equipment is crucial, requiring specialized cleaning agents and a thorough cleaning process to thoroughly remove any residue and ensure proper operation and production efficiency of the extruder.

[0003] CN106978277A discloses a method for preparing calcium carbonate for a screw cleaning agent. The calcium carbonate used is light calcium coated on the surface of heavy calcium, and then its surface is modified with a modifier. The modification requires the addition of a crystal control agent, a pH adjuster, ethylene bisstearamide, polyethylene glycol, lauryl ether phosphate, diethylene glycol butyl ether, ethyl acetate, etc., and the system temperature and pH value must be strictly controlled in the middle. Although the amount of cleaning material is saved, the modification steps are cumbersome and the preparation is difficult.

[0004] CN102618401A discloses a twin-screw high-efficiency and environmentally friendly granulation particle cleaning agent and a production method thereof. The main components are 10-30 parts of base resin, 60-80 parts of inorganic powder, 0-10 parts of lubricant, and 0-10 parts of coupling agent. The cleaning purpose is achieved by mechanical friction between a large amount of inorganic powder and the screw, but the cleaning efficiency is low.

[0005] CN105924931A discloses a method for preparing a high-efficiency plastic screw cleaning agent. However, a large amount of glass fiber is added. During use, mechanical friction between the filler and the screw accelerates screw damage. Furthermore, these fillers have poor fluidity and poor compatibility with the resin, resulting in severe self-residue in the absence of shear force at the die head.

[0006] CN106674723A discloses a screw cleaner for plastic extruders or injection molding machines, used for cleaning the barrel and screw of an extruder or injection molding machine. The cleaner is composed of 25%-40% glass fiber, a hard cleaning agent, 5%-10% PPA, an interface cleaning agent, and 50%-70% matrix resin. This cleaner has the advantage of quickly, effectively, and efficiently cleaning various adhesive substances from the barrel and screw surfaces, greatly improving cleaning efficiency. However, it also has significant disadvantages: the use of a high proportion of glass fiber removes stubborn residues through mechanical friction, which can cause irreversible damage to the screw.

[0007] There is an urgent need to develop a screw cleaning material that is environmentally friendly, has strong cleaning ability and does not damage the screw. Summary of the Invention

[0008] As described above, in order to solve the problems of easy agglomeration, uneven dispersion, insufficient cleaning power, and easy damage to the screw existing in the screw cleaning material, the purpose of the present invention is to provide a screw cleaning material that is environmentally friendly, has strong cleaning ability and does not cause damage to the screw, as well as its preparation method and application.

[0009] To this end, in a first aspect, the present invention provides a screw cleaning material, the raw materials of which include:

[0010]

[0011] The modified inorganic filler is an inorganic filler modified by an alcohol compound and a silane coupling agent.

[0012] In the screw cleaning material of the present invention, the modified inorganic filler is modified with an alcohol compound and a silane coupling agent, thereby improving the dispersibility of the inorganic filler and the bonding strength between the inorganic filler and the matrix resin. The present invention selects a matrix resin, a modified inorganic filler, a surfactant, a compatibilizer, and an antioxidant to compound the modified inorganic filler. The modified inorganic filler can be more evenly dispersed in the resin matrix. Furthermore, through the interaction of physical friction and chemical reactions between the various components, dirt on the screw surface can be efficiently and thoroughly removed without damaging the screw.

[0013] In some preferred embodiments of the present invention, the modified inorganic filler is an inorganic filler modified sequentially with an alcohol compound and a silane coupling agent. In the screw cleaning compound of the present invention, the modified inorganic filler is first dispersed using the alcohol compound. The alcohol compound not only serves as a solvent but also improves the dispersibility of the inorganic powder. The addition of the silane coupling agent strengthens the bonding between the inorganic filler and the matrix resin. The synergistic effect of the two improves the modification effect compared to other dispersants.

[0014] In some embodiments of the present invention, the screw cleaning material does not contain glass fiber and strong alkaline reagents, such as sodium hydroxide and potassium hydroxide. Therefore, the screw cleaning material provided by the present invention has the advantages of being environmentally friendly and not easily damaging the screw.

[0015] In some embodiments of the present invention, the inorganic filler is selected from at least one of calcium carbonate, magnesium oxide and zinc oxide.

[0016] In some embodiments of the present invention, the silane coupling agent is selected from at least one of γ-aminopropyltriethoxysilane, γ-(2,3-epoxypropoxy)propyltrimethoxysilane and vinyltriethoxysilane, preferably at least two.

[0017] In some embodiments of the present application, the alcohol compound is selected from at least one of methanol, ethanol, ethylene glycol, propanol, n-pentanol, preferably at least one of ethanol, ethylene glycol, propanol, n-pentanol. The above-mentioned alcohol compound has moderate evaporation speed, which can relatively reduce the agglomeration between particles during the drying process, and is beneficial to obtain mixed powder with good dispersity.

[0018] In some embodiments of the present application, the mass ratio of inorganic filler to alcohol compound in the raw material of the modified inorganic filler is 1:6-8.

[0019] In some embodiments of the present application, the mass ratio of inorganic filler to silane coupling agent in the raw material of the modified inorganic filler is 3-6:1.

[0020] In some embodiments of the present application, the inorganic filler is calcium carbonate and zinc oxide, and the mass ratio of calcium carbonate to zinc oxide is 6-0.7:1, preferably 5-3:3. The present application selects specific proportions of calcium carbonate and zinc oxide as inorganic fillers, so that the screw cleaning material not only has a small amount, but also reduces the cleaning time and has a significant cleaning effect.

[0021] In some embodiments of the present application, the preparation method of the modified inorganic filler comprises: immersing the inorganic filler in the alcohol compound for ultrasonic dispersion, then filtering and first drying to obtain inorganic filler dispersion material, spraying the silane coupling agent solution into the inorganic filler dispersion material, and then stirring and second drying.

[0022] The inorganic filler is immersed in the alcohol compound for ultrasonic dispersion, so that the inorganic filler is fully dispersed in ethanol. Then, the silane coupling agent is uniformly covered on the surface of the filler by spraying, which not only saves the amount of silane coupling agent, but also ensures the uniformity and stability of the modification effect of the modified inorganic filler, thereby improving the comprehensive performance of the material. Moreover, compared with the conventional modification method of simple mixing, the above-mentioned step-by-step modification method can more accurately control the modification process, improve the uniformity and stability of the modification effect, and thus improve the comprehensive performance of the material.

[0023] In some embodiments of the present application, the ultrasonic dispersion conditions include: temperature 20-35℃, time 5-20min, and ultrasonic power 100-500w under stirring.

[0024] In some embodiments of the present application, the concentration of the silane coupling agent solution is 40-60wt%.

[0025] In some embodiments of the present application, the solvent of the silane coupling agent solution is selected from at least one of methanol, ethanol, ethylene glycol, propanol, n-pentanol, preferably at least one of ethanol, ethylene glycol, propanol, n-pentanol.

[0026] In some embodiments of the present invention, the base resin is selected from at least one of polypropylene resin and polyethylene resin.

[0027] In some preferred embodiments of the present invention, the matrix resin is selected from at least one polypropylene resin. The present invention utilizes polypropylene resin and modified inorganic fillers as solid particles, which act as physical friction during the cleaning process, helping to remove stubborn dirt from the screw surface. Under the shear force of the screw, these particles are better able to adhere to the screw surface, removing dirt through friction. Furthermore, the modified inorganic filler has improved compatibility with the matrix resin and can also remove impurities such as resin remaining on the screw. The particles of polypropylene and modified calcium carbonate have a certain surface charge and functional groups, which can adsorb or chemically react with dirt on the screw surface, further enhancing the cleaning effect.

[0028] In some embodiments of the present invention, the surfactant is selected from at least one of polyoxyethylene lauryl ether phosphate salts, alkyl phosphates, dodecyl dimethyl benzyl ammonium chloride, and alkylphenol polyoxyethylene ether.

[0029] In some embodiments of the present invention, the compatibilizer is selected from at least one of maleic anhydride grafted polypropylene.

[0030] In some embodiments of the present invention, the antioxidant is selected from pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and tris[2,4-di-tert-butylphenyl]phosphite, and the mass ratio between the two is 1:0.5-2.

[0031] In some embodiments of the present invention, the surfactant is selected from at least two of polyoxyethylene lauryl ether phosphate salts, alkyl phosphates, dodecyl dimethyl benzyl ammonium chloride and alkylphenol polyoxyethylene ether.

[0032] In some preferred embodiments of the present invention, the alkyl phosphate is a C8-C12 alkyl phosphate.

[0033] In some preferred embodiments of the present invention, the alkylphenol polyoxyethylene ether is a C8-C12 alkylphenol polyoxyethylene ether.

[0034] In some embodiments of the present invention, the surfactant is selected from dodecyldimethylbenzyl ammonium chloride (DDBAC) and alkylphenol polyoxyethylene ether, with a mass ratio of 1:0.5-2. The solid particles in the cleaning compound, combined with the excellent wetting and penetrating properties of DDBAC and alkylphenol polyoxyethylene ether, reduce the surface tension of the material, allowing the cleaning agent to more easily penetrate into the tiny gaps on the screw surface, thereby improving the cleaning effect.

[0035] In some embodiments of the present invention, the base resin is selected from at least one copolymerized polypropylene resin, and the copolymerized polypropylene resin has a melt index of 2-10 g / 10 min at 230° C. and a load of 2.16 kg.

[0036] To this end, in a second aspect, the present invention provides a method for preparing the above-mentioned screw cleaning material, comprising the following steps: mixing the raw materials, melt-extruding and strand-granulating.

[0037] In some preferred embodiments of the present invention, the mixing conditions include: a rotation speed of 500-800 r / min and a time of 15-30 min.

[0038] In some preferred embodiments of the present invention, the conditions for melt extrusion include: the temperature of each zone of the screw extruder is 180±5°C in zone 1, 190±5°C in zone 2, 200±5°C in zone 3, 205±5°C in zone 4, 200±5°C in zone 5, 190±5°C in zone 6, 185±5°C in zone 7, 190±5°C in zone 8, 200±5°C in zone 9, 205±5°C in zone 10, 205±5°C in the die head, and the speed is 400-500r / min.

[0039] To this end, in a third aspect, the present invention provides a method for cleaning a screw of a processing equipment, comprising the following steps: adding the above-mentioned screw cleaning material or the screw cleaning material obtained by the above-mentioned preparation method into the processing equipment for cleaning.

[0040] In some preferred embodiments of the present invention, the processing equipment is a screw extruder.

[0041] In some preferred embodiments of the present invention, the cleaning conditions include: the temperature of each zone of the screw extruder is: 190±5℃, 200±5℃ in zone 2, 210±5℃ in zone 3, 215±5℃ in zone 4, 210±5℃ in zone 5, 200±5℃ in zone 6, 195±5℃ in zone 7, 200±5℃ in zone 8, 210±5℃ in zone 9, 215±5℃ in zone 10, 215±5℃ in die head, the speed is 400-500r / min, and the pressure is 3-5MPa.

[0042] Cleaning under these temperatures can soften and melt stubborn stains, such as carbonized polymers formed on the screw surface after high-temperature processing, making them easier to remove with the cleaning compound. Furthermore, these temperatures can accelerate chemical reactions, such as those between the active ingredients in the cleaning compound and the stains, enhancing cleaning efficiency.

[0043] In addition, the temperature during cleaning is slightly higher than the temperature for preparing the cleaning material, which can reduce the viscosity of the cleaning material, enhance the flowability, and make the cleaning material better penetrate into every corner, gap and complex structure of the screw, so as to ensure that there is no dead angle in cleaning. Moreover, the cleaning material provided by the application has good thermal stability, and the temperature during cleaning has no adverse effect on the cleaning material.

[0044] The cleaning condition is under the above pressure, first, the physical damage caused by the screw, such as deformation of the screw, can be avoided, so as to affect the subsequent normal material conveying, plasticizing and mixing functions of the screw; second, the non-uniform spraying of the cleaning material caused by the excessively high pressure can be avoided. Under the above pressure, the cleaning material can fully contact every surface of the screw, so as to avoid the cleaning material passing through some channels too fast due to excessive force, and thus cannot fully stay and play a cleaning role on the entire surface of the screw, which affects the cleaning quality; third, the splashing of the cleaning material caused by the excessively high pressure can be avoided, which can cause pollution of the working place and waste the cleaning material, and increase the cleaning cost.

[0045] The application has the following beneficial effects:

[0046] 1. In the screw cleaning material of the application, the modified inorganic filler is modified by an alcohol compound and a silane coupling agent, which can improve the dispersibility of the inorganic filler and the bonding force between the inorganic filler and the matrix resin. The application selects a matrix resin, a modified inorganic filler, a surfactant, a compatibilizer and an antioxidant for compounding, the modified inorganic filler can be more uniformly dispersed in the resin matrix, and through the mutual cooperation between the physical friction and chemical action of each component, the dirt on the surface of the screw can be efficiently and completely removed without causing damage to the screw.

[0047] 2. In the screw cleaning material of the application, polypropylene resin and modified inorganic filler are preferably used as solid particles, which play a role of physical friction in the cleaning process and help to remove stubborn dirt on the surface of the screw. These particles can better adhere to the surface of the screw under the action of the shearing force of the screw, remove the dirt through friction, and the modified inorganic filler and the matrix resin have better compatibility, which can also take away the impurities such as resin remaining on the screw. The surface of polypropylene and modified calcium carbonate carries a certain charge and functional groups, which can adsorb or chemically react with the dirt on the surface of the screw, further enhancing the cleaning effect.

[0048] 3. The application preferably selects calcium carbonate and zinc oxide in a specific ratio as inorganic fillers, so that the screw cleaning material has less usage and shorter cleaning time, and the cleaning effect is remarkable. BRIEF DESCRIPTION OF DRAWINGS

[0049] Figure 1 (a) and 1(b) are respectively the washed-out material after the screw of the extruder is washed out by using the cleaning material prepared in Example 2.

[0050] Figure 1 (c) The rinse-out material after the end of the cleaning of the extruder screw using the cleaning material prepared in Example 2.

[0051] Figure 1 (d) The extruded material obtained after the end of the cleaning of Example 2 and the re-feeding of the raw material into the extruder and the subsequent heating. DETAILED DESCRIPTION

[0052] The technical solutions of the present application are further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments are only used to help understand the present application and should not be regarded as specific limitations of the present application. The specific conditions not mentioned in the embodiments are carried out according to the conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments used are not marked with the manufacturer and are all conventional products that can be obtained by purchase.

[0053] (I) Raw materials

[0054] The polypropylene resin PP is PP-2500HY (melt index of 2.2 g / 10 min at 230℃ under a load of 2.16 kg);

[0055] The nonylphenol polyoxyethylene ether is purchased from Sinopharm Wakayama Reagent, CAS No. 127087-87-0.

[0056] (II) Methods

[0057] The test method of the melt index is in accordance with GB / T-3682.

[0058] Example 1

[0059] Preparation of modified inorganic filler

[0060] After weighing 25 g of calcium carbonate and 15 g of zinc oxide, immerse them in 300 g of anhydrous ethanol, stir under ultrasonic conditions at room temperature (25℃) for 10 min, and then dry to obtain the dispersed mixed powder.

[0061] Dissolve 10 g of silane coupling agent KH-550 in anhydrous ethanol to prepare a 50 wt% solution, spray it on the dispersed mixed powder, stir for 30 min, and dry to remove the anhydrous ethanol in the mixed powder to obtain the modified mixed powder.

[0062] Preparation of screw cleaning material

[0063] Raw materials: polypropylene resin PP, dodecyl dimethyl benzyl ammonium chloride, nonylphenol polyoxyethylene ether, maleic anhydride grafted PP, antioxidant 1010 and antioxidant 168. The specific amounts are shown in Table 1.

[0064] The above raw materials and modified mixed powder are added to the mixer, mixed at a speed of 600r / min for 30min at room temperature of 25℃ and dry environment, and the screw extruder parameters are adjusted as follows: zone 1 180℃, zone 2 190℃, zone 3 200℃, zone 4 205℃, zone 5 200℃, zone 6 190℃, zone 7 185℃, zone 8 190℃, zone 9 200℃, zone 10 205℃, die head 205℃, speed of 400r / min, melt extrusion and strand granulation to obtain screw cleaning material.

[0065] Example 2

[0066] Preparation of modified inorganic fillers

[0067] 20 g of calcium carbonate and 15 g of zinc oxide were weighed, immersed in 250 g of anhydrous ethanol, stirred at room temperature (25° C.) for 10 min under ultrasonic conditions, and then dried to obtain a dispersed mixed powder.

[0068] 9g of silane coupling agent KH-550 was dissolved in anhydrous ethanol to prepare a 50wt% solution, which was sprayed into the dispersed mixed powder and stirred for 30min. The anhydrous ethanol in the mixed powder was removed by drying to obtain a modified mixed powder.

[0069] Preparation of screw cleaning material

[0070] Raw materials: polypropylene resin PP, dodecyl dimethyl benzyl ammonium chloride, nonylphenol polyoxyethylene ether, maleic anhydride grafted PP, antioxidant 1010 and antioxidant 168. Specific amounts are shown in Table 1.

[0071] The above raw materials and modified mixed powder are added to the mixer, mixed at a speed of 600r / min for 30min at room temperature of 25℃ and dry environment, and the screw extruder parameters are adjusted as follows: zone 1 180℃, zone 2 190℃, zone 3 200℃, zone 4 205℃, zone 5 200℃, zone 6 190℃, zone 7 185℃, zone 8 190℃, zone 9 200℃, zone 10 205℃, die head 205℃, speed of 400r / min, melt extrusion and strand granulation to obtain screw cleaning material.

[0072] Example 3

[0073] Preparation of modified inorganic fillers

[0074] 15 g of calcium carbonate and 15 g of zinc oxide were weighed, immersed in 200 g of anhydrous ethanol, stirred at room temperature (25° C.) for 10 min under ultrasonic conditions, and then dried to obtain a dispersed mixed powder.

[0075] 8g of silane coupling agent KH-550 was dissolved in anhydrous ethanol to prepare a 50wt% solution, which was sprayed into the dispersed mixed powder and stirred for 30min. The anhydrous ethanol in the mixed powder was removed by drying to obtain a modified mixed powder.

[0076] Preparation of screw cleaning material

[0077] Raw materials: polypropylene resin PP, dodecyl dimethyl benzyl ammonium chloride, nonylphenol polyoxyethylene ether, maleic anhydride grafted PP, antioxidant 1010 and antioxidant 168. Specific amounts are shown in Table 1.

[0078] The above raw materials and modified mixed powder are added to the mixer, mixed at a speed of 600r / min for 30min at room temperature of 25℃ and dry environment, and the screw extruder parameters are adjusted as follows: zone 1 180℃, zone 2 190℃, zone 3 200℃, zone 4 205℃, zone 5 200℃, zone 6 190℃, zone 7 185℃, zone 8 190℃, zone 9 200℃, zone 10 205℃, die head 205℃, speed of 400r / min, melt extrusion and strand granulation to obtain screw cleaning material.

[0079] Example 4

[0080] Preparation of modified inorganic fillers

[0081] 25 g of calcium carbonate and 10 g of zinc oxide were weighed, immersed in 250 g of anhydrous ethanol, stirred at room temperature (25° C.) for 10 min under ultrasonic conditions, and then dried to obtain a dispersed mixed powder.

[0082] 9g of silane coupling agent KH-550 was dissolved in anhydrous ethanol to prepare a 50wt% solution, which was sprayed into the dispersed mixed powder and stirred for 30min. The anhydrous ethanol in the mixed powder was removed by drying to obtain a modified mixed powder.

[0083] Preparation of screw cleaning material

[0084] Raw materials: polypropylene resin PP, dodecyl dimethyl benzyl ammonium chloride, nonylphenol polyoxyethylene ether, maleic anhydride grafted PP, antioxidant 1010 and antioxidant 168. Specific amounts are shown in Table 1.

[0085] The above raw materials and modified mixed powder are added to the mixer, mixed at a speed of 600r / min for 30min at room temperature of 25℃ and dry environment, and the screw extruder parameters are adjusted as follows: zone 1 180℃, zone 2 190℃, zone 3 200℃, zone 4 205℃, zone 5 200℃, zone 6 190℃, zone 7 185℃, zone 8 190℃, zone 9 200℃, zone 10 205℃, die head 205℃, speed of 400r / min, melt extrusion and strand granulation to obtain screw cleaning material.

[0086] Example 5

[0087] Preparation of modified inorganic fillers

[0088] 30 g of calcium carbonate and 5 g of zinc oxide were weighed, immersed in 250 g of anhydrous ethanol, stirred at room temperature (25° C.) for 10 min under ultrasonic conditions, and then dried to obtain a dispersed mixed powder.

[0089] 9g of silane coupling agent KH-550 was dissolved in anhydrous ethanol to prepare a 50wt% solution, which was sprayed into the dispersed mixed powder and stirred for 30min. The anhydrous ethanol in the mixed powder was removed by drying to obtain a modified mixed powder.

[0090] Preparation of screw cleaning material

[0091] Raw materials: polypropylene resin PP, dodecyl dimethyl benzyl ammonium chloride, nonylphenol polyoxyethylene ether, maleic anhydride grafted PP, antioxidant 1010 and antioxidant 168. Specific amounts are shown in Table 1.

[0092] The above raw materials and modified mixed powder are added to the mixer, mixed at a speed of 600r / min for 30min at room temperature of 25℃ and dry environment, and the screw extruder parameters are adjusted as follows: zone 1 180℃, zone 2 190℃, zone 3 200℃, zone 4 205℃, zone 5 200℃, zone 6 190℃, zone 7 185℃, zone 8 190℃, zone 9 200℃, zone 10 205℃, die head 205℃, speed of 400r / min, melt extrusion and strand granulation to obtain screw cleaning material.

[0093] Example 6

[0094] Preparation of modified inorganic fillers

[0095] 15 g of calcium carbonate and 20 g of zinc oxide were weighed, immersed in 250 g of anhydrous ethanol, stirred at room temperature (25° C.) for 10 min under ultrasonic conditions, and then dried to obtain a dispersed mixed powder.

[0096] 9g of silane coupling agent KH-550 was dissolved in anhydrous ethanol to prepare a 50wt% solution, which was sprayed into the dispersed mixed powder and stirred for 30min. The anhydrous ethanol in the mixed powder was removed by drying to obtain a modified mixed powder.

[0097] Preparation of screw cleaning material

[0098] Raw materials: polypropylene resin PP, dodecyl dimethyl benzyl ammonium chloride, nonylphenol polyoxyethylene ether, maleic anhydride grafted PP, antioxidant 1010 and antioxidant 168. Specific amounts are shown in Table 1.

[0099] The above raw materials and modified mixed powder are added to the mixer, mixed at a speed of 600r / min for 30min at room temperature of 25℃ and dry environment, and the screw extruder parameters are adjusted as follows: zone 1 180℃, zone 2 190℃, zone 3 200℃, zone 4 205℃, zone 5 200℃, zone 6 190℃, zone 7 185℃, zone 8 190℃, zone 9 200℃, zone 10 205℃, die head 205℃, speed of 400r / min, melt extrusion and strand granulation to obtain screw cleaning material.

[0100] Example 7

[0101] Preparation of modified inorganic fillers

[0102] 24 g of calcium carbonate and 12 g of zinc oxide were weighed, immersed in 250 g of anhydrous ethanol, stirred at room temperature (25° C.) for 10 min under ultrasonic conditions, and then dried to obtain a dispersed mixed powder.

[0103] 10g of silane coupling agent KH-550 was dissolved in anhydrous ethanol to prepare a 50wt% solution, which was sprayed into the dispersed mixed powder and stirred for 30min. The anhydrous ethanol in the mixed powder was removed by drying to obtain a modified mixed powder.

[0104] Preparation of screw cleaning material

[0105] Raw materials: polypropylene resin PP, dodecyl dimethyl benzyl ammonium chloride, nonylphenol polyoxyethylene ether, maleic anhydride grafted PP, antioxidant 1010 and antioxidant 168. Specific amounts are shown in Table 1.

[0106] The above raw materials and modified mixed powder are added to the mixer, mixed at a speed of 600r / min for 30min at room temperature of 25℃ and dry environment, and the screw extruder parameters are adjusted as follows: zone 1 180℃, zone 2 190℃, zone 3 200℃, zone 4 205℃, zone 5 200℃, zone 6 190℃, zone 7 185℃, zone 8 190℃, zone 9 200℃, zone 10 205℃, die head 205℃, speed of 400r / min, melt extrusion and strand granulation to obtain screw cleaning material.

[0107] Example 8

[0108] The difference from Example 2 is that the polypropylene resin PP-2500HY is replaced by the polyethylene resin PE-2420H (melt index is 0.9 g / 10 min at 190° C. and a load of 2.16 kg).

[0109] Example 9

[0110] The difference from Example 2 is that zinc oxide is replaced by magnesium oxide.

[0111] Example 10

[0112] The difference from Example 2 is that zinc oxide is replaced by calcium carbonate.

[0113] Example 11

[0114] The difference from Example 2 is that calcium carbonate is replaced by zinc oxide.

[0115] Example 12

[0116] The difference from Example 2 is that the mass of KH-550 is replaced from 9 g to 3 g.

[0117] Example 13

[0118] The difference from Example 2 is that dodecyldimethylbenzyl ammonium chloride is replaced by nonylphenol polyoxyethylene ether.

[0119] Example 14

[0120] The difference from Example 2 is that nonylphenol polyoxyethylene ether is replaced by dodecyldimethylbenzyl ammonium chloride.

[0121] Comparative Example 1

[0122] Preparation of screw cleaning material

[0123] Raw materials: polypropylene resin PP, calcium carbonate, vinyl bisstearamide EBS, antioxidant 1010 and antioxidant 168. See Table 1 for specific amounts.

[0124] Add the above raw materials into a mixer and mix them thoroughly at a speed of 600r / min under room temperature of 25°C and a dry environment. Adjust the screw extruder parameters as follows: zone 1 180°C, zone 2 190°C, zone 3 200°C, zone 4 205°C, zone 5 200°C, zone 6 190°C, zone 7 185°C, zone 8 190°C, zone 9 200°C, zone 10 205°C, die head 205°C, speed of 400r / min, melt extrusion and strand granulation to obtain screw cleaning material.

[0125] Comparative Example 2

[0126] Preparation of modified inorganic fillers

[0127] Weigh 20g of calcium carbonate and 15g of zinc oxide and mix them evenly to obtain a mixed powder. Dissolve 9g of silane coupling agent KH-550 in anhydrous ethanol to prepare a 50wt% solution, spray it into the mixed powder, stir at room temperature (25°C) for 30 minutes, and dry to remove the anhydrous ethanol in the mixed powder to obtain a modified mixed powder.

[0128] The screw cleaning material was prepared in the same manner as in Example 1.

[0129] Comparative Example 3

[0130] Preparation of inorganic fillers

[0131] 20 g of calcium carbonate and 15 g of zinc oxide were weighed, immersed in 250 g of anhydrous ethanol, stirred at room temperature (25° C.) for 10 min under ultrasonic conditions, and then dried to obtain a dispersed mixed powder.

[0132] The screw cleaning material was prepared in the same manner as in Example 1.

[0133] Comparative Example 4

[0134] Preparation of modified inorganic fillers

[0135] 20 g of calcium carbonate and 15 g of zinc oxide were weighed, immersed in an aqueous solution of desugared condensed sodium lignin sulfonate with a concentration of 0.8 wt%, stirred at room temperature (25° C.) for 10 min under ultrasonic conditions, and then dried to obtain a dispersed mixed powder.

[0136] 9g of silane coupling agent KH-550 was dissolved in anhydrous ethanol to prepare a 50wt% solution, which was sprayed into the dispersed mixed powder and stirred for 30min. The anhydrous ethanol in the mixed powder was removed by drying to obtain a modified mixed powder.

[0137] The screw cleaning material was prepared in the same manner as in Example 2.

[0138] Comparative Example 5

[0139] Preparation of modified inorganic fillers

[0140] 20 g of calcium carbonate and 15 g of zinc oxide were weighed, immersed in an aqueous solution of desugared condensed sodium lignin sulfonate with a concentration of 0.8 wt%, stirred at room temperature (25° C.) for 10 min under ultrasonic conditions, and then dried to obtain a dispersed mixed powder.

[0141] 9g of silane coupling agent KH-550 was dissolved in water to prepare a 50wt% solution, which was sprayed into the dispersed mixed powder and stirred for 30min. The anhydrous ethanol in the mixed powder was removed by drying to obtain a modified mixed powder.

[0142] The screw cleaning material was prepared in the same manner as in Example 2.

[0143] Table 1

[0144]

[0145]

[0146] Test Example 1

[0147] The screw cleaning material prepared by each of the above examples and comparative examples was used to clean the twin-screw extruder.

[0148] The twin-screw extruder was used to produce acrylonitrile-butadiene-styrene copolymer ABS black switching transparent polycarbonate PC. Taking the cleaning of ABS black as an example, the screw cleaning material was added to the twin-screw extruder. The temperature of each zone of the twin-screw extruder was as follows: 200°C for the first zone, 210°C for the second zone, 220°C for the third zone, 230°C for the fourth zone, 240°C for the fifth zone, 240°C for the sixth zone, 230°C for the seventh zone, 220°C for the eighth zone, 210°C for the ninth zone, 215°C for the tenth zone, and 210°C for the head. The rotation speed was 400 r / min, and the pressure was 3-5 MPa. The cleaning was continuously performed until the extrudate met the requirements that the color of the extruded rubber block was consistent with that of the raw material, and there were no color lines or black spots, that is, until the screw was cleaned. Finally, the amount of the cleaning material and the time consumed were recorded. The test results are shown in Table 2.

[0149] Table 2

[0150]

[0151]

[0152] As can be seen from Tables 1-2, the screw cleaning materials prepared in Examples 1-14 have remarkable cleaning effects. In particular, Examples 1-7 use a specific ratio of calcium carbonate and zinc oxide as inorganic fillers, so that the final product achieves a unique balance and synergistic effect in performance, and has a remarkable cleaning effect. That is, under the action of the shear force of the screw, the mixed and modified powder in the ratio can better adhere to the surface of the screw, remove dirt through friction, and the modified calcium carbonate and zinc oxide have better compatibility with the matrix resin, and can also take away impurities such as resin remaining on the screw, and the effect is much better than using single calcium carbonate as a filler, which can save at least 38% of the cleaning time and 50% of the cleaning material; at most, 75% of the cleaning time and 65% of the cleaning material can be saved.

[0153] Compared with Examples 9-11, Example 2 uses a specific ratio of calcium carbonate and zinc oxide as inorganic fillers, which significantly reduces the amount of cleaning material and saves cleaning time.

[0154] Comparative Examples 2 and 3 differ from Example 2 in the modification method of the inorganic fillers. The amount of the cleaning material used is 20 kg and 25 kg more than that of Example 2, respectively, and the cleaning time is 30 min and 35 min more than that of Example 2, respectively. That is, the cleaning effect of the modified inorganic fillers prepared in the application is obviously better than that of the ordinary inorganic fillers.

[0155] Compared with Example 2, Comparative Examples 4 and 5 use desugared condensed sodium lignin sulfonate instead of ethanol. Although desugared condensed sodium lignin sulfonate can be used as a dispersant, the cleaning effects of Comparative Examples 4 and 5 are significantly worse, that is, the cleaning material prepared by the present invention has significantly better effect.

[0156] It should be noted that the embodiments described above are only used to explain the present invention and do not constitute any limitation of the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory words, rather than restrictive words. The present invention may be modified as specified within the scope of the claims of the present invention, and the present invention may be revised without departing from the scope and spirit of the present invention. Although the present invention described therein relates to specific methods, materials and embodiments, it does not mean that the present invention is limited to the specific examples disclosed therein. On the contrary, the present invention can be extended to all other methods and applications with the same function.

Claims

1. A screw cleaning material, characterized in that: The raw materials of the screw cleaning material include, by weight: 50-60 parts of base resin, 30-45 parts of modified inorganic filler, 1-5 parts of surfactant, Compatibilizer 0.5-5 parts, 0.2-3 parts of antioxidant; The modified inorganic filler is an inorganic filler modified by an alcohol compound and a silane coupling agent; the inorganic filler is calcium carbonate and zinc oxide, and the mass ratio of the calcium carbonate to zinc oxide is 5-3:3; The preparation method of the modified inorganic filler comprises: immersing the inorganic filler in an alcohol compound, performing ultrasonic dispersion, filtering, and first drying to obtain an inorganic filler dispersion; spraying a silane coupling agent solution into the inorganic filler dispersion, stirring, and then performing a second drying; The matrix resin is selected from at least one copolymerized polypropylene resin, wherein the melt index of the copolymerized polypropylene resin is 2-10 g / 10 min at 230° C. and a load of 2.16 kg; The surfactant is selected from dodecyl dimethyl benzyl ammonium chloride and alkylphenol polyoxyethylene ether, and the mass ratio of the two is 1:0.5-2.

2. The screw cleaning material according to claim 1, characterized in that The silane coupling agent is at least one selected from γ-aminopropyltriethoxysilane, γ-(2,3-epoxypropoxy)propyltrimethoxysilane and vinyltriethoxysilane; and / or The alcohol compound is selected from at least one of methanol, ethanol, ethylene glycol, propanol, and n-pentanol; and / or In the raw materials of the modified inorganic filler, the mass ratio of the inorganic filler to the alcohol compound is 1:6-8; and / or In the raw materials of the modified inorganic filler, the mass ratio of the inorganic filler to the silane coupling agent is 3-6:

1.

3. The screw cleaning material according to claim 1, characterized in that The ultrasonic dispersion conditions include: under stirring, temperature 20-35° C., time 5-20 min, ultrasonic power 100-500 watts; and / or The concentration of the silane coupling agent solution is 40-60wt%; and / or The solvent of the silane coupling agent solution is selected from at least one of methanol, ethanol, ethylene glycol, propanol, and n-pentanol.

4. The screw cleaning material according to any one of claims 1 to 3, characterized in that: The compatibilizer is selected from at least one of maleic anhydride grafted polypropylene; and / or The antioxidant is selected from pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and tris[2,4-di-tert-butylphenyl]phosphite, and the mass ratio of the two is 1:0.5-2.

5. The method for preparing the screw cleaning material according to any one of claims 1 to 4, characterized in that: The following steps are involved: After the raw materials are mixed, they are melt extruded and pelletized.

6. A screw cleaning method for processing equipment, characterized in that: The method comprises the following steps: adding the screw cleaning material according to any one of claims 1 to 4 or the screw cleaning material prepared by the preparation method according to claim 5 into processing equipment for cleaning.

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