Waterproof and wear-resistant paper-plastic composite bag and preparation method thereof

Abstract

The invention relates to the technical field of paper-plastic composite bags and discloses a waterproof and wear-resistant paper-plastic composite bag and a preparation method thereof. The invention controls the amount of catalyst added and the amount of dodecene added in the preparation process of long-chain alkyl hydrogenated silicone oil to prepare high-hydrogen-containing long-chain alkyl hydrogenated silicone oil, and adds the oil to trimethylolpropane triacrylate to prepare modified silicone oil; controls the amount of four acrylic monomers added, namely, methyl methacrylate, isooctyl acrylate, hydroxyethyl acrylate, and glycidyl methacrylate, to prepare high melt index polyacrylate and low melt index polyacrylate, which are melt-blended with sisal fiber-modified nano-alumina to prepare a polyacrylate film; and finally, hot-pressed with kraft paper to prepare a waterproof and wear-resistant paper-plastic composite bag.

Description

Technical Field

[0001] The invention relates to the technical field of paper-plastic composite bags, in particular to a waterproof and wear-resistant paper-plastic composite bag and a preparation method thereof. Background Art

[0002] Packaging bags are widely used in daily life and industrial production. Traditional paper packaging bags have environmental advantages, but their poor water and abrasion resistance can easily cause moisture and damage to items. While plastic packaging bags currently on the market offer excellent water and abrasion resistance, their environmental impact cannot be ignored.

[0003] Therefore, it is urgent to study a new type of packaging material that has both environmental advantages and good waterproof and wear-resistant properties. Summary of the Invention

[0004] The object of the present invention is to provide a waterproof and wear-resistant paper-plastic composite bag and a preparation method thereof, so as to solve the problems raised in the above background technology.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0006] A method for preparing a waterproof and wear-resistant paper-plastic composite bag comprises the following steps:

[0007] S1: adding trimethylolpropane triacrylate and long-chain alkyl hydrogenated silicone oil into a reaction vessel and mixing them evenly, adding a catalyst, and heating the reaction to obtain modified silicone oil;

[0008] S2: Methyl methacrylate, isooctyl acrylate, hydroxyethyl acrylate, glycidyl methacrylate, modified silicone oil, and initiator are uniformly mixed, added dropwise to butyl acetate, and heated for reaction to obtain a high melt index polyacrylate;

[0009] S3: Methyl methacrylate, isooctyl acrylate, hydroxyethyl acrylate, glycidyl methacrylate, and an initiator are uniformly mixed, added to butyl acetate, and heated for reaction to obtain a low melt index polyacrylate;

[0010] S4: preparing a composite masterbatch by melting, cooling, pulling, and pelletizing the wear-resistant agent and low melt index polyacrylate, then adding the composite masterbatch and high melt index polyacrylate into a blender for mixing, and extruding and blow-molding into a wear-resistant and waterproof polyacrylate film;

[0011] S5: hot pressing the wear-resistant and waterproof polyacrylate film and kraft paper to obtain a waterproof and wear-resistant paper-plastic composite bag.

[0012] Furthermore, in step S1, the long-chain alkyl hydrogenated silicone oil is prepared as follows:

[0013] Add hydrogen-containing silicone oil, tetramethyldisiloxane, and octamethylcyclotetrasiloxane into a reaction vessel and mix evenly. Add concentrated sulfuric acid, heat to 30-40°C, and stir for 12-18 hours. Add sodium carbonate and distill under reduced pressure to obtain high-hydrogen-containing silicone oil. Heat the high-hydrogen-containing silicone oil to 70-80°C, add dodecene and a catalyst dropwise, and heat to 100-105°C after the addition is completed and continue the reaction for 6-8 hours to obtain a long-chain alkyl hydrogen-containing silicone oil.

[0014] Furthermore, the mass ratio of the hydrogenated silicone oil: tetramethyldisiloxane: octamethylcyclotetrasiloxane is (2-3): 1: 1; the catalyst is a Speier catalyst, and the addition amount is 4 mg / kg; the hydrogenated silicone oil is 202 hydrogenated silicone oil; and the mass ratio of high hydrogenated silicone oil: dodecene is (100-125): (1.1-1.3).

[0015] Furthermore, in step S1, the mass ratio of trimethylolpropane triacrylate to long-chain alkyl hydrogenated silicone oil is 1:(5-8); the catalyst is a Speier catalyst, and the addition amount is 5-6 mg / kg.

[0016] Furthermore, in step S2, the components, by mass, are 10-20 parts of methyl methacrylate, 10-20 parts of isooctyl acrylate, 30-40 parts of hydroxyethyl acrylate, 40-50 parts of glycidyl methacrylate, 20-30 parts of modified silicone oil, 1-5 parts of initiator, and 80-100 parts of butyl acetate; the initiator is AIBN, the dripping rate is 1-2 g / min, the heating temperature is 80-85°C, and the time is 4-5h.

[0017] Furthermore, in step S3, the components, by mass, are 40-50 parts of methyl methacrylate, 30-40 parts of isooctyl acrylate, 10-20 parts of hydroxyethyl acrylate, 10-20 parts of glycidyl methacrylate, 1-3 parts of initiator, and 60-80 parts of butyl acetate; the heating temperature is 80-85° C., and the heating time is 4-5 hours.

[0018] Furthermore, in step S4, the anti-wear agent is prepared as follows:

[0019] 3-aminopropyl triethoxysilane and coconut oil fatty acid diethanolamide were mixed evenly, preheated to 60-65°C, added to the ethanol solution of nano-alumina, filtered, and dried to obtain modified nano-alumina;

[0020] The nano-modified alumina is ultrasonically dispersed in an acetone solution, alkali-reduced sisal fiber is added, stirred for 1-2 hours, filtered, and dried to obtain a wear-resistant agent.

[0021] Furthermore, in step S4, the mass ratio of the anti-wear agent to the low melt index polyacrylate is (4-5): (5-6); and the mass ratio of the composite masterbatch to the high melt index polyacrylate is (90-96): (4-10).

[0022] Furthermore, the melting temperature of the composite masterbatch is 165-180°C; the melting temperature of the composite masterbatch and the high melt index polyacrylate is 155-165°C; and the extrusion temperature is 220-240°C.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The invention controls the amount of catalyst and dodecene added during the preparation of long-chain alkyl hydrogenated silicone oil, thereby retaining as much Si-H as possible for subsequent polymerization to prepare polypropylene while maintaining a certain grafting rate; the prepared long-chain alkyl hydrogenated silicone oil is subjected to a hydrosilylation reaction with trimethylolpropane triacrylate to prepare a modified silicone oil with a double bond; and by controlling the amount of Si-H retained during the subsequent reaction during the preparation of the long-chain alkyl hydrogenated silicone oil, a double bond remains after the hydrosilylation reaction with trimethylolpropane triacrylate for the subsequent polymerization of polypropylene. Compared with a traditional method of adding modified silicone oil to polypropylene, the invention avoids the problem of dispersibility and the occurrence of agglomeration, achieves a tighter bond, and improves hydrophobicity and mechanical properties.

[0025] The invention prepares high melt index polyacrylate and low melt index polyacrylate by controlling the added amounts of four acrylic monomers, namely, methyl methacrylate, isooctyl acrylate, hydroxyethyl acrylate, and glycidyl methacrylate. The polyacrylate film is uniformly dispersed and tightly bonded by sequentially melt-mixing with a wear-resistant agent. Compared with the conventional direct melt blending of the wear-resistant agent and polypropylene, the conventional method has the problem of large differences in fluidity and density between the wear-resistant agent and the polypropylene, which easily causes the wear-resistant agent fibers to float on the surface during the blow molding process and easily causes the wear-resistant agent fibers to fall off during processing or use, resulting in reduced waterproof performance and wear resistance. The invention helps the wear-resistant agent to be further dispersed at a low melt flow rate by the long-chain alkyl group in the low melt index polyacrylate. After being mixed with the high melt index polyacrylate, the high melt fluidity can fill the pores and diffuse to the wear-resistant agent surface, thereby preventing the wear-resistant agent fibers from floating on the surface, causing the wear-resistant agent fibers to fall off during processing or use, resulting in reduced waterproof performance and wear resistance. DETAILED DESCRIPTION

[0026] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0027] In the following examples, methyl methacrylate CAS#: 80-62-6, 2-ethylhexyl acrylate CAS#: 104-76-7, hydroxyethyl acrylate CAS#: 818-61-1, and glycidyl methacrylate CAS#: 106-91-2 were provided by Jiangsu Qiangsheng Functional Chemical Co., Ltd., and trimethylolpropane triacrylate was provided by Qiangsheng Chemical Co., Ltd.; 202 hydrogenated silicone oil was provided by Zhejiang Hengyecheng Organic Silicone Co., Ltd.; hexamethyldisiloxane was provided by Jiangxi Pinhan New Materials Co., Ltd., and octamethylcyclotetrasiloxane was provided by Zhejiang Zhongtian Fluorosilicon Materials Co., Ltd.; sisal fiber was provided by Guangdong Guangken Oriental Sisal Co., Ltd., with a particle size of 0.08 mm, and nano-alumina particles with a particle size of 20 nm were provided by Hefei AVIC Nano-Technology Development Co., Ltd.

[0028] In the following examples, the anti-wear agent was prepared as follows:

[0029] 3-aminopropyl triethoxysilane and coconut oil fatty acid diethanolamide were mixed evenly, preheated to 60-65°C, added to the ethanol solution of nano-alumina, filtered, and dried to obtain modified nano-alumina;

[0030] The modified nano-alumina is ultrasonically dispersed in an acetone solution, alkali-reduced sisal fiber is added, stirred for 1-2 hours, filtered, and dried to obtain a wear-resistant agent.

[0031] Example 1: A method for preparing a waterproof and wear-resistant paper-plastic composite bag: S1: 80 kg of 202 hydrogenated silicone oil, 40 kg of tetramethyldisiloxane, and 40 kg of octamethylcyclotetrasiloxane were added to a reaction vessel and mixed evenly. 6 kg of concentrated sulfuric acid was added, heated to 35° C. and stirred for 12 h. 12 kg of sodium carbonate was added to neutralize the concentrated sulfuric acid, and the mixture was distilled under reduced pressure to obtain high-hydrogenated silicone oil. 100 kg of the high-hydrogenated silicone oil was heated to 70° C., 1.1 kg of dodecene and 400 mg of Speier catalyst were added dropwise, and after the addition was completed, the mixture was heated to 100° C. and the reaction was continued for 6 h to obtain a long-chain alkyl hydrogenated silicone oil.

[0032] S2: 10 kg of trimethylolpropane triacrylate and 5 kg of long-chain alkyl hydrogenated silicone oil were added to a reaction vessel and mixed evenly. 50 mg of Speier catalyst was added and heated at 100° C. for 2 h to obtain modified silicone oil.

[0033] S3: 10 kg of methyl methacrylate, 10 kg of isooctyl acrylate, 30 kg of hydroxyethyl acrylate, 50 kg of glycidyl methacrylate, 20 kg of modified silicone oil, and 1 kg of initiator AIBN were mixed evenly, and added dropwise to 80 kg of butyl acetate at a rate of 1 g / min. The mixture was heated to 85°C and reacted for 4 h to obtain a high melt index polyacrylate.

[0034] S4: 50 kg of methyl methacrylate, 30 kg of isooctyl acrylate, 10 kg of hydroxyethyl acrylate, 10 kg of glycidyl methacrylate, and 1 kg of initiator AIBN were mixed evenly, added to 60 kg of butyl acetate, and heated to 80° C. for 4 hours to obtain a low melt index polyacrylate;

[0035] S5: 40 kg of anti-wear agent and 60 kg of low melt index polyacrylate are melted at 165°C, cooled, pulled, and pelletized to prepare a composite masterbatch. Then, 90 kg of the composite masterbatch and 10 kg of high melt index polyacrylate are added to a blender and mixed at 155°C. The mixture is then extruded and blown at 220°C to form a wear-resistant and waterproof polyacrylate film. The film thickness is 20 μm.

[0036] S6: hot-pressing the wear-resistant and waterproof polyacrylate film and kraft paper to obtain a waterproof and wear-resistant paper-plastic composite bag.

[0037] Test: Contact angle test:

[0038] The contact angle of the wear-resistant and waterproof polyacrylate film surface was measured using an optical contact angle meter. The test conditions were as follows: the sitting drop method was used, and the drop size was 4 μL;

[0039] Abrasion resistance test:

[0040] The wear-resistant and waterproof polyacrylate film was tested for friction loss performance on an M2000 wear tester with a load of 250N and a wear time of 40min to test the specific wear rate.

[0041] Example 2: A method for preparing a waterproof and wear-resistant paper-plastic composite bag: S1: 80 kg of 202 hydrogenated silicone oil, 40 kg of tetramethyldisiloxane, and 40 kg of octamethylcyclotetrasiloxane were added to a reaction vessel and mixed evenly. 6 kg of concentrated sulfuric acid was added, heated to 35° C. and stirred for 12 h. 12 kg of sodium carbonate was added to neutralize the concentrated sulfuric acid, and the mixture was distilled under reduced pressure to obtain high-hydrogenated silicone oil. 100 kg of the high-hydrogenated silicone oil was heated to 70° C., 1.1 kg of dodecene and 400 mg of Speier catalyst were added dropwise, and after the addition was completed, the mixture was heated to 100° C. and the reaction was continued for 6 h to obtain a long-chain alkyl hydrogenated silicone oil.

[0042] S2: 10 kg of trimethylolpropane triacrylate and 5 kg of long-chain alkyl hydrogenated silicone oil were added to a reaction vessel and mixed evenly. 50 mg of Speier catalyst was added and heated at 100° C. for 2 h to obtain modified silicone oil.

[0043] S3: 10 kg of methyl methacrylate, 10 kg of isooctyl acrylate, 30 kg of hydroxyethyl acrylate, 50 kg of glycidyl methacrylate, 20 kg of modified silicone oil, and 1 kg of initiator AIBN were mixed evenly, and added dropwise to 80 kg of butyl acetate at a rate of 1 g / min. The mixture was heated to 85°C and reacted for 4 h to obtain a high melt index polyacrylate.

[0044] S4: 50 kg of methyl methacrylate, 30 kg of isooctyl acrylate, 10 kg of hydroxyethyl acrylate, 10 kg of glycidyl methacrylate, and 1 kg of initiator AIBN were mixed evenly, added to 60 kg of butyl acetate, and heated to 80° C. for 4 hours to obtain a low melt index polyacrylate;

[0045] S5: 50 kg of anti-wear agent and 50 kg of low melt index polyacrylate are melted at 165°C, cooled, pulled, and pelletized to prepare a composite masterbatch. 96 kg of the composite masterbatch and 4 kg of high melt index polyacrylate are added to a blender and mixed at 155°C. The mixture is then extruded and blown at 220°C to form a wear-resistant and waterproof polyacrylate film. The film thickness is 20 μm.

[0046] S6: hot-pressing the wear-resistant and waterproof polyacrylate film and kraft paper to obtain a waterproof and wear-resistant paper-plastic composite bag.

[0047] Test: Contact angle test:

[0048] The contact angle of the wear-resistant and waterproof polyacrylate film surface was measured using an optical contact angle meter. The test conditions were as follows: the sitting drop method was used, and the drop size was 4 μL;

[0049] Abrasion resistance test:

[0050] The wear-resistant and waterproof polyacrylate film was tested for friction loss performance on an M2000 wear tester with a load of 250N and a wear time of 40min to test the specific wear rate.

[0051] Example 3: A method for preparing a waterproof and wear-resistant paper-plastic composite bag: S1: 80 kg of 202 hydrogenated silicone oil, 40 kg of tetramethyldisiloxane, and 40 kg of octamethylcyclotetrasiloxane were added to a reaction vessel and mixed evenly. 6 kg of concentrated sulfuric acid was added, heated to 35° C. and stirred for 12 h. 12 kg of sodium carbonate was added to neutralize the concentrated sulfuric acid, and the mixture was distilled under reduced pressure to obtain high-hydrogenated silicone oil. 100 kg of the high-hydrogenated silicone oil was heated to 70° C., 1.1 kg of dodecene and 400 mg of Speier catalyst were added dropwise. After the addition was completed, the mixture was heated to 100° C. and the reaction was continued for 6 h to obtain a long-chain alkyl hydrogenated silicone oil.

[0052] S2: 10 kg of trimethylolpropane triacrylate and 5 kg of long-chain alkyl hydrogenated silicone oil were added to a reaction vessel and mixed evenly. 50 mg of Speier catalyst was added and heated at 100° C. for 2 h to obtain modified silicone oil.

[0053] S3: 10 kg of methyl methacrylate, 10 kg of isooctyl acrylate, 30 kg of hydroxyethyl acrylate, 50 kg of glycidyl methacrylate, 30 kg of modified silicone oil, and 1 kg of initiator AIBN were mixed evenly, and added dropwise to 80 kg of butyl acetate at a rate of 1 g / min. The mixture was heated to 85°C and reacted for 4 h to obtain a high melt index polyacrylate.

[0054] S4: 50 kg of methyl methacrylate, 30 kg of isooctyl acrylate, 10 kg of hydroxyethyl acrylate, 10 kg of glycidyl methacrylate, and 1 kg of initiator AIBN were mixed evenly, added to 60 kg of butyl acetate, and heated to 80° C. for 4 hours to obtain a low melt index polyacrylate;

[0055] S5: 50 kg of anti-wear agent and 50 kg of low melt index polyacrylate are melted at 165°C, cooled, pulled, and pelletized to prepare a composite masterbatch. 96 kg of the composite masterbatch and 4 kg of high melt index polyacrylate are added to a blender and mixed at 155°C. The mixture is then extruded and blown at 220°C to form a wear-resistant and waterproof polyacrylate film. The film thickness is 20 μm.

[0056] S6: hot-pressing the wear-resistant and waterproof polyacrylate film and kraft paper to obtain a waterproof and wear-resistant paper-plastic composite bag.

[0057] Test: Contact angle test:

[0058] The contact angle of the wear-resistant and waterproof polyacrylate film surface was measured using an optical contact angle meter. The test conditions were as follows: the sitting drop method was used, and the drop size was 4 μL;

[0059] Abrasion resistance test:

[0060] The wear-resistant and waterproof polyacrylate film was tested for friction loss performance on an M2000 wear tester with a load of 250N and a wear time of 40min to test the specific wear rate.

[0061] Comparative Example 1: A method for preparing a waterproof and wear-resistant paper-plastic composite bag: S1: 80 kg of 202 hydrogenated silicone oil, 40 kg of tetramethyldisiloxane, and 40 kg of octamethylcyclotetrasiloxane were added to a reaction vessel and mixed evenly; 6 kg of concentrated sulfuric acid was added, heated to 35° C. and stirred for 12 h; 12 kg of sodium carbonate was added to neutralize the concentrated sulfuric acid, and vacuum distillation was performed to obtain high-hydrogenated silicone oil; 100 kg of high-hydrogenated silicone oil was heated to 70° C., 1.1 kg of dodecene and 500 mg of Speier catalyst were added dropwise, and after the addition was completed, the mixture was heated to 100° C. and the reaction was continued for 6 h to obtain long-chain alkyl hydrogenated silicone oil;

[0062] The remaining steps are the same as those in Example 1.

[0063] Comparative Example 2: A method for preparing a waterproof and wear-resistant paper-plastic composite bag: S1: 80 kg of 202 hydrogenated silicone oil, 40 kg of tetramethyldisiloxane, and 40 kg of octamethylcyclotetrasiloxane were added to a reaction vessel and mixed evenly; 6 kg of concentrated sulfuric acid was added, heated to 35° C. and stirred for 12 h; 12 kg of sodium carbonate was added to neutralize the concentrated sulfuric acid, and vacuum distillation was performed to obtain high-hydrogenated silicone oil; 100 kg of high-hydrogenated silicone oil was heated to 70° C., 1.1 kg of dodecene and 300 mg of Speier catalyst were added dropwise, and after the addition was completed, the mixture was heated to 100° C. and the reaction was continued for 6 h to obtain long-chain alkyl hydrogenated silicone oil;

[0064] The remaining steps are the same as those in Example 1.

[0065] Comparative Example 3: A method for preparing a waterproof and wear-resistant paper-plastic composite bag: S1: 80 kg of 202 hydrogenated silicone oil, 40 kg of tetramethyldisiloxane, and 40 kg of octamethylcyclotetrasiloxane were added to a reaction vessel and mixed evenly. 6 kg of concentrated sulfuric acid was added, heated to 35° C. and stirred for 12 h. 12 kg of sodium carbonate was added to neutralize the concentrated sulfuric acid, and vacuum distillation was performed to obtain high-hydrogenated silicone oil. 100 kg of high-hydrogenated silicone oil was heated to 70° C., 1.4 kg of dodecene and 400 mg of Speier catalyst were added dropwise, and after the addition was completed, the mixture was heated to 100° C. and the reaction was continued for 6 h to obtain long-chain alkyl hydrogenated silicone oil.

[0066] The remaining steps are the same as those in Example 1.

[0067] Comparative Example 4: A method for preparing a waterproof and wear-resistant paper-plastic composite bag: S1: 80 kg of 202 hydrogen-containing silicone oil, 40 kg of tetramethyldisiloxane, and 40 kg of octamethylcyclotetrasiloxane were added to a reaction vessel and mixed evenly. 6 kg of concentrated sulfuric acid was added, heated to 35° C. and stirred for 12 h. 12 kg of sodium carbonate was added to neutralize the concentrated sulfuric acid, and vacuum distillation was performed to obtain high-hydrogen-containing silicone oil. 100 kg of high-hydrogen-containing silicone oil was heated to 70° C., 1.0 kg of dodecene and 400 mg of Speier catalyst were added dropwise, and after the addition was completed, the mixture was heated to 100° C. and the reaction was continued for 6 h to obtain long-chain alkyl hydrogen-containing silicone oil.

[0068] The remaining steps are the same as those in Example 1.

[0069] Comparative Example 5: Example 1: A method for preparing a waterproof and wear-resistant paper-plastic composite bag: S1: 80 kg of 202 hydrogen-containing silicone oil, 40 kg of tetramethyldisiloxane, and 40 kg of octamethylcyclotetrasiloxane were added to a reaction vessel and mixed evenly, 6 kg of concentrated sulfuric acid was added, heated to 35 ° C and stirred for 12 hours, 12 kg of sodium carbonate was added to neutralize the concentrated sulfuric acid, and vacuum distillation was performed to obtain high-hydrogen-containing silicone oil; 100 kg of high-hydrogen-containing silicone oil was heated to 70 ° C, 1.1 kg of dodecene and 400 mg of Speier catalyst were added dropwise, and after the addition was completed, the mixture was heated to 100 ° C and the reaction was continued for 6 hours to obtain long-chain alkyl hydrogen-containing silicone oil;

[0070] S2: 10 kg of trimethylolpropane triacrylate and 5 kg of long-chain alkyl hydrogenated silicone oil were added to a reaction vessel and mixed evenly. 50 mg of Speier catalyst was added and heated at 100° C. for 2 h to obtain modified silicone oil.

[0071] S3: 10 kg of methyl methacrylate, 10 kg of isooctyl acrylate, 30 kg of hydroxyethyl acrylate, 50 kg of glycidyl methacrylate, 20 kg of modified silicone oil and 1 kg of initiator AIBN were mixed evenly, and added dropwise to 80 kg of butyl acetate at a rate of 1 g / min, and heated to 85°C for 4 h to obtain polyacrylate;

[0072] S5: 40 kg of anti-wear agent and 60 kg of polypropylene are melted at 165°C, cooled, pulled, and extruded and blown at 220°C to form a wear-resistant and waterproof polyacrylate film; the film thickness is 20 μm;

[0073] S6: hot-pressing the wear-resistant and waterproof polyacrylate film and kraft paper to obtain a waterproof and wear-resistant paper-plastic composite bag.

[0074] Test: Contact angle test:

[0075] The contact angle of the wear-resistant and waterproof polyacrylate film surface was measured using an optical contact angle meter. The test conditions were as follows: the sitting drop method was used, and the drop size was 4 μL;

[0076] Abrasion resistance test:

[0077] The wear-resistant and waterproof polyacrylate film was tested for friction loss performance on an M2000 wear tester with a load of 250N and a wear time of 40min to test the specific wear rate.

[0078]

[0079] Conclusion: The polyacrylate films prepared in Examples 1-3 have excellent waterproof and friction resistance.

[0080] In Comparative Example 1, too much catalyst was added to prepare the long-chain alkyl hydrogenated silicone oil; in Comparative Example 2, too little catalyst was added to prepare the long-chain alkyl hydrogenated silicone oil; in Comparative Example 3, too much dodecene was added to prepare the long-chain alkyl hydrogenated silicone oil; and in Comparative Example 4, too little dodecene was added to prepare the long-chain alkyl hydrogenated silicone oil; in Comparative Example 5, the anti-wear agent was directly melt-blended with polypropylene to prepare the polyacrylate film, which resulted in reduced waterproof and wear resistance of the prepared film.

[0081] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or substitute equivalents for some of the technical features. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A method for preparing a waterproof and wear-resistant paper-plastic composite bag, characterized in that: The following steps are involved: S1: adding trimethylolpropane triacrylate and long-chain alkyl hydrogenated silicone oil into a reaction vessel and mixing them evenly, adding a catalyst, and heating the reaction to obtain modified silicone oil; S2: Methyl methacrylate, isooctyl acrylate, hydroxyethyl acrylate, glycidyl methacrylate, modified silicone oil, and initiator are uniformly mixed, added dropwise to butyl acetate, and heated for reaction to obtain a high melt index polyacrylate; S3: Methyl methacrylate, isooctyl acrylate, hydroxyethyl acrylate, glycidyl methacrylate, and an initiator are uniformly mixed, added to butyl acetate, and heated for reaction to obtain a low melt index polyacrylate; S4: preparing a composite masterbatch by melting, cooling, pulling, and pelletizing the wear-resistant agent and low melt index polyacrylate, then adding the composite masterbatch and high melt index polyacrylate into a blender for melt mixing, and extruding and blow molding into a wear-resistant and waterproof polyacrylate film; S5: hot pressing the wear-resistant and waterproof polyacrylate film and kraft paper to obtain a waterproof and wear-resistant paper-plastic composite bag; In step S1, long-chain alkyl hydrogenated silicone oil is prepared as follows: Add hydrogenated silicone oil, tetramethyldisiloxane, and octamethylcyclotetrasiloxane into a reaction vessel and mix evenly; add concentrated sulfuric acid, heat to 30-40°C, and stir for 12-18 hours; add sodium carbonate, and distill under reduced pressure to obtain high hydrogenated silicone oil; heat the high hydrogenated silicone oil to 70-80°C, add dodecene and a catalyst dropwise, and heat to 100-105°C after the addition is complete and continue the reaction for 6-8 hours to obtain long-chain alkyl hydrogenated silicone oil; In the preparation process of long-chain alkyl hydrogenated silicone oil, the catalyst is a Speier catalyst, the mass ratio of high hydrogenated silicone oil:catalyst is 1kg:4mg; the mass ratio of high hydrogenated silicone oil:dodecene is (100-125):(1.1-1.3).

2. The method for preparing a waterproof and wear-resistant paper-plastic composite bag according to claim 1, characterized in that: The mass ratio of hydrogen-containing silicone oil: tetramethyldisiloxane: octamethylcyclotetrasiloxane is (2-3): 1: 1; the hydrogen-containing silicone oil is 202 hydrogen-containing silicone oil.

3. The method for preparing a waterproof and wear-resistant paper-plastic composite bag according to claim 1, characterized in that: In step S1, the mass ratio of trimethylolpropane triacrylate to long-chain alkyl hydrogenated silicone oil is 1:(5-8); and the catalyst is a Speier catalyst.

4. The method for preparing a waterproof and wear-resistant paper-plastic composite bag according to claim 1, characterized in that: In step S2, the components of the high melt index polyacrylate are calculated by weight: 10-20 parts of methyl methacrylate, 10-20 parts of isooctyl acrylate, 30-40 parts of hydroxyethyl acrylate, 40-50 parts of glycidyl methacrylate, 20-30 parts of modified silicone oil, 1-5 parts of initiator, and 80-100 parts of butyl acetate; the initiator is AIBN, the dripping rate is 1-2 g / min, the heating temperature is 80-85°C, and the time is 4-5h.

5. The method for preparing a waterproof and wear-resistant paper-plastic composite bag according to claim 1, characterized in that: In step S3, the components of the low melt index polyacrylate are, by weight, 40-50 parts of methyl methacrylate, 30-40 parts of isooctyl acrylate, 10-20 parts of hydroxyethyl acrylate, 10-20 parts of glycidyl methacrylate, 1-3 parts of initiator, and 60-80 parts of butyl acetate; the heating temperature is 80-85° C., and the time is 4-5 hours.

6. The method for preparing a waterproof and wear-resistant paper-plastic composite bag according to claim 1, characterized in that: In step S4, the anti-wear agent is prepared as follows: 3-aminopropyl triethoxysilane and coconut oil fatty acid diethanolamide were mixed evenly, preheated to 60-65°C, added to the ethanol solution of nano-alumina, filtered, and dried to obtain modified nano-alumina; The modified nano-alumina is ultrasonically dispersed in an acetone solution, alkali-reduced sisal fiber is added, stirred for 1-2 hours, filtered, and dried to obtain a wear-resistant agent.

7. The method for preparing a waterproof and wear-resistant paper-plastic composite bag according to claim 1, characterized in that: In step S4, the mass ratio of the anti-wear agent to the low melt index polyacrylate is (4-5): (5-6); the mass ratio of the composite masterbatch to the high melt index polyacrylate is (90-96): (4-10).

8. The method for preparing a waterproof and wear-resistant paper-plastic composite bag according to claim 1, characterized in that: In step S4, the melting temperature for preparing the composite masterbatch is 165-180°C; the temperature for melt mixing the composite masterbatch and the high melt index polyacrylate is 155-165°C; and the extrusion temperature is 220-240°C.

9. A paper-plastic composite bag prepared according to the method for preparing a waterproof and wear-resistant paper-plastic composite bag according to any one of claims 1 to 8.

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