A rubber compound based on an industrial printing roller and a method for producing the same

Abstract

The application relates to the technical field of high polymer materials, and discloses a mixing rubber based on an industrial printing rubber roller and a preparation method thereof. The preparation steps are as follows: adding ethylene-propylene-diene rubber and methyl vinyl silicone rubber into a banbury mixer, mixing, adding a photoinitiator, modified filler, active agent and stearic acid, mixing, adding a softening agent, mixing, adding a crosslinking agent and an accelerator, mixing uniformly, thin passing on an open mill, and preparing the mixing rubber. The mixing rubber comprises the following raw materials in parts by mass: 90-100 parts of ethylene-propylene-diene rubber, 5-10 parts of methyl vinyl silicone rubber, 2-4 parts of a photoinitiator, 90-100 parts of modified filler, 10-12 parts of active agent, 2-5 parts of stearic acid, 20-25 parts of a softening agent, 5-8 parts of a crosslinking agent, and 3-4 parts of an accelerator.

Description

A compound rubber based on industrial printing rollers and its preparation method Technical Field

[0001] This invention relates to the field of polymer materials technology, and discloses a compound rubber based on industrial printing rollers and its preparation method. Background Technology

[0002] The printing industry requires multiple sets of rubber rollers to transfer ink to the printing plate. Printing rollers are composites made of elastic rubber and a metal core through a specific process. The compound rubber used on their surface is one of the key factors affecting the performance of printing rollers, thus requiring several excellent properties: During high-speed operation, printing rollers need to withstand significant pressure and shear forces; therefore, the compound rubber must possess sufficient mechanical properties to prevent damage during use. Simultaneously, the compound rubber needs good heat aging resistance to ensure stable performance of the rollers over long-term use. Currently, the rubber used in rollers is generally EPDM rubber, a typical hydrophobic material. However, water is often added as a solvent in current printing inks; therefore, the rollers need a certain degree of hydrophilicity to improve ink transfer during printing. In summary, researching a compound rubber with good mechanical properties, good aging resistance, and good hydrophilicity for industrial printing rollers, and its preparation method, is of great significance. Summary of the Invention

[0003] The purpose of this invention is to provide a compound rubber based on industrial printing rollers and its preparation method, so as to solve the problems mentioned in the background art.

[0004] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a method for preparing a compound rubber based on industrial printing rollers, comprising the following steps: adding EPDM rubber and methyl vinyl silicone rubber to a mixer and mixing them evenly; adding photoinitiator 2-isopropylthioxanthone, filler, activator zinc oxide, and stearic acid and mixing them evenly; adding a softener and mixing them evenly; adding a crosslinking agent dicumyl peroxide and an accelerator N-cyclohexyl-2-benzothiazole sulfenamide and mixing them evenly; and passing the mixture through a two-roll mill to obtain the compound rubber.

[0005] In a more optimized manner, the compound comprises the following raw materials, by weight parts: 90-100 parts EPDM rubber, 5-10 parts methyl vinyl silicone rubber, 2-4 parts photoinitiator, 90-100 parts filler, 10-12 parts activator, 2-5 parts stearic acid, 20-25 parts softener, 5-8 parts crosslinking agent, and 3-4 parts accelerator.

[0006] Ideally, the filler comprises carbon black.

[0007] More optimally, the filler is modified carbon black, which is modified to obtain the modified filler before being added. The preparation method of the modified filler is as follows: concentrated sulfuric acid and concentrated nitric acid are mixed evenly, carbon black is added, the temperature is raised to 120-130℃ and reacted for 0.5-1h, filtered, washed with water and dried; antioxidant RD and acetone are added, mixed evenly, and high-pressure ground for 2-5min, cyclodextrin composition is added, high-pressure ground for 2-5min, and dried to obtain the modified filler; the grinding speed is 12000r / min and the grinding pressure is 1.2MPa.

[0008] In a more optimized manner, the modified filler comprises the following raw materials, by mass parts: 10-12 parts concentrated sulfuric acid, 20-30 parts concentrated nitric acid, 15-20 parts carbon black, 1-1.5 parts antioxidant, 10-15 parts acetone, and 4-6 parts cyclodextrin composition.

[0009] In a more optimized manner, the compound comprises the following raw materials, by mass parts: 90-100 parts EPDM rubber, 5-10 parts methyl vinyl silicone rubber, 2-4 parts photoinitiator, 90-100 parts modified filler, 10-12 parts activator, 2-5 parts stearic acid, 20-25 parts softener, 5-8 parts crosslinking agent, and 3-4 parts accelerator.

[0010] More optimally, the cyclodextrin composition includes allyl-β-cyclodextrin, carboxymethyl-β-cyclodextrin, and modified β-cyclodextrin; the preparation of the modified β-cyclodextrin includes the following steps: adding carboxymethyl-β-cyclodextrin to toluene, ultrasonically dispersing it evenly, adding excess terephthalic diisocyanate, heating to 70-80°C under nitrogen protection, stirring and reacting for 10-15 hours, removing the solvent to obtain isocyanate-modified cyclodextrin, adding excess water, ultrasonically dispersing it evenly, heating to 40-50°C and stirring and reacting for 8-12 hours, removing the solvent to obtain modified β-cyclodextrin.

[0011] More preferably, the cyclodextrin composition comprises allyl-β-cyclodextrin, carboxymethyl-β-cyclodextrin, or modified β-cyclodextrin in a mass ratio of 1:(0.5-0.8):(1-2).

[0012] In a more optimized manner, the modified β-cyclodextrin comprises the following raw materials, by mass parts: 5-10 parts carboxymethyl-β-cyclodextrin, 50-80 parts terephthalic diisocyanate, and 500-800 parts water.

[0013] More preferably, the softener is a hyperbranched tung oil softener, and the preparation method includes the following steps: take tung oil, methanol and potassium hydroxide, mix them evenly, react at 60-70℃ for 1-2 hours, let stand and separate the liquid to take the upper layer, wash until neutral, remove water, and obtain methyl tungate.

[0014] Take methyl tung acid and maleic anhydride, stir evenly, and heat to 85-90℃ under nitrogen protection for 2-3 hours. After the reactants are cooled to room temperature, add acetone and stir evenly. Adjust the pH to 7 with NaOH, remove the acetone, and add cyclohexane and water to remove unreacted substances. Take the aqueous layer, add excess NaOH, and saponify at 75℃ for 2-3 hours. Acidify by adding hydrochloric acid dropwise. Dissolve the crude product in ethyl acetate, add NaSO4 and dry for 12 hours. After filtration, remove ethyl acetate to obtain solid tung acid.

[0015] Tung oil softener was obtained by mixing tung oil trisaccharide, polyethylene glycol diglycidyl ether, triphenylphosphine, and isobutanol evenly and refluxing at 108°C for 45–55 h, removing the solvent, and then obtaining hyperbranched tung oil softener.

[0016] More preferably, the methyl tung oil comprises the following raw materials, by mass parts: 60-70 parts tung oil, 15-20 parts methanol, and 1-2 parts potassium hydroxide; the tung oil triglyceride comprises the following raw materials, by mass parts: 35-45 parts methyl tung oil and 8-12 parts maleic anhydride; the hyperbranched tung oil softener comprises the following raw materials, by mass parts: 15-20 parts tung oil triglyceride, 20-25 parts polyethylene glycol diglycidyl ether, 0.1-0.2 parts triphenylphosphine, and 40-50 parts isobutanol.

[0017] Compared with the prior art, the beneficial effects achieved by this invention are as follows: using hyperbranched tung oil as a softener, the long carbon chain has good compatibility with the matrix rubber, while the multiple hydrophilic groups at the ends migrate to the material surface to form a hydrophilic film layer due to the polarity difference between the hydrophilic groups and the matrix rubber, thus improving the surface hydrophilicity; its hyperbranched structure can improve the toughness of the matrix rubber while forming a physical entanglement network to prevent detachment, thereby maintaining excellent hydrophilicity for a long time; the softener also introduces MW400 polyethylene glycol diglycidyl ether to further improve the overall hydrophilicity. The amount and molecular weight of this substance should not be too large, otherwise the excessive hydrophilicity will lead to a decrease in compatibility with the matrix rubber, which will result in a decrease in performance.

[0018] A modified filler was prepared by combining an antioxidant, carbon black, and cyclodextrin composition using high-speed grinding to improve the dispersibility of the carbon black and antioxidant. The cyclodextrin composition included allyl-β-cyclodextrin, carboxymethyl-β-cyclodextrin, and modified β-cyclodextrin in a certain mass ratio. Cyclodextrin can further improve the migration of antioxidants and enhance the aging resistance by utilizing its own molecular cavity structure. Among them, allyl-β-cyclodextrin contains a double bond structure, which can improve the degree of crosslinking and the overall compatibility of the modified filler with the rubber matrix during subsequent vulcanization. Carboxymethyl-β-cyclodextrin contains multiple hydrophilic groups, which further improves hydrophilicity. Modified β-cyclodextrin is first isocyanated and then reacted with water to obtain modified β-cyclodextrin containing an aniline structure, which helps to improve the anti-aging performance.

[0019] In summary, the compound prepared by this invention, comprising EPDM rubber, methyl vinyl silicone rubber, modified filler, and hyperbranched tung oil softener, exhibits excellent mechanical properties, aging resistance, and hydrophilicity. Furthermore, during vulcanization, the components undergo further crosslinking, enhancing compatibility and crosslinking degree, thereby further improving overall performance. Detailed Implementation

[0020] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] It should be noted that there are no special restrictions on the manufacturers of the raw materials involved in this invention. Exemplary examples include: ethylene propylene diene monomer (EPDM) (Dow NORDEL 3430); methyl vinyl silicone rubber (Shanghai Yuanye T22921); 2-isopropylthioxanthone (CAS: 5495-84-1); zinc oxide activator (Karnos); stearic acid (CAS: 57-11-4); dicumyl peroxide (CAS: 80-43-3); N-cyclohexyl-2-benzothiazole sulfenamide (CAS: 95-33-0); tung oil (Hunan) Beijusheng JS0277); Methanol (CAS: 67-56-1); Potassium hydroxide (CAS: 1310-58-3); Polyethylene glycol diglycidyl ether (Shanghai Yuanye, MW: 400); Concentrated sulfuric acid (80%); Concentrated nitric acid (68%); Carbon black (rubber carbon black 330); Antioxidant RD (Yuanye S97687); Allyl-β-cyclodextrin (Xi'an Qiyue 2311); Carboxymethyl-β-cyclodextrin (Shandong Binzhou Zhiyuan Biotechnology Co., Ltd. ZY-21-001); Terephthalic diisocyanate (CAS: 104-49-4);

[0022] Unless otherwise specified, all figures below are parts by weight or mass ratios.

[0023] Example 1: S1: Take 65 parts tung oil, 20 parts methanol, and 1 part potassium hydroxide, mix them evenly, react at 70°C for 2 hours, let stand and separate the liquid, wash until neutral, remove water by rotary evaporation to obtain methyl tungate; take 40 parts methyl tungate and 10 parts maleic anhydride, stir evenly, heat to 88°C under nitrogen protection and react for 2 hours, after the reactants cool to room temperature, add 200 parts acetone and stir evenly, adjust the pH to 7 with NaOH, remove the acetone, and add cyclohexane. Unreacted substances were removed with water; the aqueous layer was collected, excess NaOH was added, and the reaction was carried out at 75°C for 3 hours. Hydrochloric acid was added dropwise for acidification. The crude product was dissolved in ethyl acetate, and dried with NaSO4 for 12 hours. After filtration, ethyl acetate was removed to obtain tungsten triglyceride. 18 parts of tungsten triglyceride, 25 parts of polyethylene glycol diglycidyl ether, 0.15 parts of triphenylphosphine, and 50 parts of isobutanol were stirred evenly and refluxed at 108°C for 48 hours. The solvent was removed to obtain a softener.

[0024] S2: Add 6 parts of carboxymethyl-β-cyclodextrin to 50 parts of toluene, disperse evenly by ultrasonication, add 80 parts of terephthalic diisocyanate, heat to 70°C under nitrogen protection, stir and react for 12 hours, remove the solvent to obtain isocyanate-modified cyclodextrin, add 800 parts of water, disperse evenly by ultrasonication, heat to 45°C and stir and react for 10 hours, remove the solvent to obtain modified β-cyclodextrin; take allyl-β-cyclodextrin, carboxymethyl-β-cyclodextrin and modified β-cyclodextrin in a mass ratio of 1:0.6:1.5, mix evenly to obtain cyclodextrin composition;

[0025] S3: Mix 10 parts concentrated sulfuric acid and 25 parts concentrated nitric acid evenly, add 20 parts carbon black, heat to 130℃ and react for 0.5 h, filter, wash with water and dry, add 1 part antioxidant RD and 15 parts acetone, mix evenly, grind under high pressure for 2 min, then add 4 parts cyclodextrin composition, grind under high pressure for 5 min, dry to obtain modified filler; the grinding speed is 12000 r / min and the grinding pressure is 1.2 MPa;

[0026] S4: Add 100 parts of EPDM rubber and 5 parts of methyl vinyl silicone rubber to a mixer and mix evenly. Add 4 parts of photoinitiator 2-isopropylthioxanthraquinone, 100 parts of modified filler, 10 parts of activator zinc oxide, and 2 parts of stearic acid and mix evenly. Add 25 parts of softener and mix evenly. Add 5 parts of crosslinking agent dicumyl peroxide and 3.5 parts of N-cyclohexyl-2-benzothiazole sulfenamide and mix evenly. Pass the mixture through a two-roll mill to obtain the compound.

[0027] Example 2: S1: Take 60 parts tung oil, 20 parts methanol, and 1 part potassium hydroxide, mix them evenly, react at 70°C for 2 hours, let stand and separate the liquid, wash until neutral, remove water by rotary evaporation to obtain methyl tungate; take 35 parts methyl tungate and 8 parts maleic anhydride, stir evenly, heat to 88°C under nitrogen protection and react for 2 hours, wait for the reactants to cool to room temperature, add 200 parts acetone and stir evenly, adjust the pH to 7 with NaOH, remove the acetone, add cyclohexane and Unreacted substances were removed with water; the aqueous layer was collected, excess NaOH was added, and the reaction was carried out at 75°C for 3 hours. Hydrochloric acid was added dropwise for acidification, and the crude product was dissolved in ethyl acetate. NaSO4 was added and dried for 12 hours. After filtration, ethyl acetate was removed to obtain tungsten triglyceride; 15 parts of tungsten triglyceride, 20 parts of polyethylene glycol diglycidyl ether, 0.15 parts of triphenylphosphine, and 50 parts of isobutanol were stirred evenly and refluxed at 108°C for 48 hours. The solvent was removed to obtain a softener.

[0028] S2: Add 6 parts of carboxymethyl-β-cyclodextrin to 50 parts of toluene, disperse evenly by ultrasonication, add 80 parts of terephthalic diisocyanate, heat to 70°C under nitrogen protection, stir and react for 12 hours, remove the solvent to obtain isocyanate-modified cyclodextrin, add 800 parts of water, disperse evenly by ultrasonication, heat to 45°C and stir and react for 10 hours, remove the solvent to obtain modified β-cyclodextrin; mix allyl-β-cyclodextrin, carboxymethyl-β-cyclodextrin and modified β-cyclodextrin in a mass ratio of 1:0.8:1.2 evenly to obtain a cyclodextrin composition;

[0029] S3: Mix 10 parts concentrated sulfuric acid and 30 parts concentrated nitric acid evenly, add 20 parts carbon black, heat to 130℃ and react for 0.5 h, filter, wash with water and dry, add 1 part antioxidant RD and 15 parts acetone, mix evenly, grind under high pressure for 2 min, then add 4 parts cyclodextrin composition, grind under high pressure for 5 min, dry to obtain modified filler; the grinding speed is 12000 r / min and the grinding pressure is 1.2 MPa;

[0030] S4: Add 100 parts of EPDM rubber and 5 parts of methyl vinyl silicone rubber to a mixer and mix evenly. Add 4 parts of photoinitiator 2-isopropylthioxanthraquinone, 100 parts of modified filler, 10 parts of activator zinc oxide, and 2 parts of stearic acid and mix evenly. Add 25 parts of softener and mix evenly. Add 5 parts of crosslinking agent dicumyl peroxide and 3.5 parts of N-cyclohexyl-2-benzothiazole sulfenamide and mix evenly. Pass the mixture through a two-roll mill to obtain the compound.

[0031] Example 3: S1: Take 70 parts tung oil, 20 parts methanol, and 2 parts potassium hydroxide, mix them evenly, react at 70°C for 2 hours, let stand and separate the liquid, wash until neutral, remove water by rotary evaporation to obtain methyl tungate; take 45 parts methyl tungate and 12 parts maleic anhydride, stir evenly, heat to 88°C under nitrogen protection and react for 2 hours, after the reactants cool to room temperature, add 200 parts acetone and stir evenly, adjust the pH to 7 with NaOH, remove the acetone, and add cyclohexane. Unreacted substances were removed with water; the aqueous layer was collected, excess NaOH was added, and the reaction was carried out at 75°C for 3 hours. Hydrochloric acid was added dropwise for acidification. The crude product was dissolved in ethyl acetate, dried with NaSO4 for 12 hours, filtered, and the ethyl acetate was removed to obtain tungsten triglyceride; 20 parts of tungsten triglyceride, 25 parts of polyethylene glycol diglycidyl ether, 0.15 parts of triphenylphosphine, and 50 parts of isobutanol were stirred evenly and refluxed at 108°C for 48 hours. The solvent was removed to obtain a softener.

[0032] S2: Add 6 parts of carboxymethyl-β-cyclodextrin to 50 parts of toluene, disperse evenly by ultrasonication, add 80 parts of terephthalic diisocyanate, heat to 70°C under nitrogen protection, stir and react for 12 hours, remove the solvent to obtain isocyanate-modified cyclodextrin, add 800 parts of water, disperse evenly by ultrasonication, heat to 45°C and stir and react for 10 hours, remove the solvent to obtain modified β-cyclodextrin; mix allyl-β-cyclodextrin, carboxymethyl-β-cyclodextrin and modified β-cyclodextrin evenly in a mass ratio of 1:0.8:2 to obtain a cyclodextrin composition;

[0033] S3: Mix 12 parts concentrated sulfuric acid and 20 parts concentrated nitric acid evenly, add 20 parts carbon black, heat to 130℃ and react for 1 hour, filter, wash with water and dry, add 1 part antioxidant RD and 15 parts acetone, mix evenly, grind under high pressure for 2 minutes, then add 4 parts cyclodextrin composition, grind under high pressure for 5 minutes, dry to obtain modified filler; the grinding speed is 12000 r / min and the grinding pressure is 1.2 MPa;

[0034] S4: Add 100 parts of EPDM rubber and 5 parts of methyl vinyl silicone rubber to a mixer and mix evenly. Add 4 parts of photoinitiator 2-isopropylthioxanthraquinone, 100 parts of modified filler, 10 parts of activator zinc oxide, and 2 parts of stearic acid and mix evenly. Add 25 parts of softener and mix evenly. Add 5 parts of crosslinking agent dicumyl peroxide and 3.5 parts of N-cyclohexyl-2-benzothiazole sulfenamide and mix evenly. Pass the mixture through a two-roll mill to obtain the compound.

[0035] Comparative Example 1 (using paraffin oil as a softener, the remaining steps are the same as in Example 1): S1: 6 parts of carboxymethyl-β-cyclodextrin were added to 50 parts of toluene and ultrasonically dispersed evenly. 80 parts of terephthalic diisocyanate were added, and the mixture was heated to 70°C under nitrogen protection and stirred for 12 hours. The solvent was removed to obtain isocyanate-modified cyclodextrin. 800 parts of water were added and ultrasonically dispersed evenly. The mixture was heated to 45°C and stirred for 10 hours. The solvent was removed to obtain modified β-cyclodextrin. Allyl-β-cyclodextrin, carboxymethyl-β-cyclodextrin, and modified β-cyclodextrin in a mass ratio of 1:0.6:1.5 were mixed evenly to obtain a cyclodextrin composition.

[0036] S2: Mix 10 parts concentrated sulfuric acid and 25 parts concentrated nitric acid evenly, add 20 parts carbon black, heat to 130℃ and react for 0.5 h, filter, wash with water and dry, add 1 part antioxidant RD and 15 parts acetone, mix evenly, grind under high pressure for 2 min, then add 4 parts cyclodextrin composition, grind under high pressure for 5 min, dry to obtain modified filler; the grinding speed is 12000 r / min and the grinding pressure is 1.2 MPa;

[0037] S3: Add 100 parts of EPDM rubber and 5 parts of methyl vinyl silicone rubber to a mixer and mix evenly. Add 4 parts of photoinitiator 2-isopropylthioxanthraquinone, 100 parts of modified filler, 10 parts of activator zinc oxide, and 2 parts of stearic acid and mix evenly. Add 25 parts of paraffin oil softener and mix evenly. Add 5 parts of crosslinking agent dicumyl peroxide and 3.5 parts of N-cyclohexyl-2-benzothiazole sulfenamide and mix evenly. Pass the mixture through a two-roll mill to obtain the compound.

[0038] Comparative Example 2 (modified β-cyclodextrin instead of cyclodextrin composition, the remaining methods and steps are the same as in Example 1): S1: Take 65 parts of tung oil, 20 parts of methanol, and 1 part of potassium hydroxide, mix them evenly, react at 70°C for 2 hours, let stand and separate the liquid, wash until neutral, remove water by rotary evaporation to obtain methyl tungate; Take 40 parts of methyl tungate and 10 parts of maleic anhydride, stir evenly, heat to 88°C under nitrogen protection and react for 2 hours, wait for the reactants to cool to room temperature, add 200 parts of acetone and stir evenly, and adjust the pH with NaOH. Adjust to 7, remove acetone, add cyclohexane and water to remove unreacted substances; take the aqueous layer, add excess NaOH, saponify at 75℃ for 3h, acidify with hydrochloric acid dropwise, dissolve the crude product in ethyl acetate, add NaSO4 to dry for 12h, filter to remove ethyl acetate, and obtain tungmatriic acid; mix 18 parts tungmatriic acid, 25 parts polyethylene glycol diglycidyl ether, 0.15 parts triphenylphosphine, and 50 parts isobutanol, stir evenly, reflux at 108℃ for 48h, remove the solvent, and obtain the softener;

[0039] S2: Add 6 parts of carboxymethyl-β-cyclodextrin to 50 parts of toluene, disperse evenly by ultrasonication, add 80 parts of terephthalic diisocyanate, heat to 70°C under nitrogen protection, keep warm and stir for 12 hours, remove the solvent to obtain isocyanate-modified cyclodextrin, add 800 parts of water, disperse evenly by ultrasonication, heat to 45°C and stir for 10 hours, remove the solvent to obtain modified β-cyclodextrin.

[0040] S3: Mix 10 parts concentrated sulfuric acid and 25 parts concentrated nitric acid evenly, add 20 parts carbon black, heat to 130℃ and react for 0.5 h, filter, wash with water and dry, add 1 part antioxidant RD and 15 parts acetone, mix evenly, grind under high pressure for 2 min, then add 4 parts modified β-cyclodextrin, grind under high pressure for 5 min, dry to obtain modified filler; the grinding speed is 12000 r / min and the grinding pressure is 1.2 MPa;

[0041] S4: Add 100 parts of EPDM rubber and 5 parts of methyl vinyl silicone rubber to a mixer and mix evenly. Add 4 parts of photoinitiator 2-isopropylthioxanthraquinone, 100 parts of modified filler, 10 parts of activator zinc oxide, and 2 parts of stearic acid and mix evenly. Add 25 parts of softener and mix evenly. Add 5 parts of crosslinking agent dicumyl peroxide and 3.5 parts of N-cyclohexyl-2-benzothiazole sulfenamide and mix evenly. Pass the mixture through a two-roll mill to obtain the compound.

[0042] Comparative Example 3 (without combining antioxidants, carbon black, and cyclodextrin; all other steps are the same as in Example 1): S1: Take 65 parts tung oil, 20 parts methanol, and 1 part potassium hydroxide, mix thoroughly, react at 70°C for 2 hours, allow to stand, separate the upper layer, wash until neutral, and remove water by rotary evaporation to obtain methyl tungate; Take 40 parts methyl tungate and 10 parts maleic anhydride, stir thoroughly, and react at 88°C for 2 hours under nitrogen protection. After the reactants cool to room temperature, add 200 parts acetone and stir thoroughly. Use NaOH to remove p H was adjusted to 7, acetone was removed, and cyclohexane and water were added to remove unreacted substances. The aqueous layer was collected, excess NaOH was added, and the reaction was carried out at 75°C for 3 hours. Hydrochloric acid was added dropwise for acidification. The crude product was dissolved in ethyl acetate, and NaSO4 was added for drying for 12 hours. After filtration, ethyl acetate was removed to obtain tungsten triglyceride. 18 parts of tungsten triglyceride, 25 parts of polyethylene glycol diglycidyl ether, 0.15 parts of triphenylphosphine, and 50 parts of isobutanol were stirred evenly and refluxed at 108°C for 48 hours. The solvent was removed to obtain a softener.

[0043] S2: Add 6 parts of carboxymethyl-β-cyclodextrin to 50 parts of toluene, disperse evenly by ultrasonication, add 80 parts of terephthalic diisocyanate, heat to 70°C under nitrogen protection, stir and react for 12 hours, remove the solvent to obtain isocyanate-modified cyclodextrin, add 800 parts of water, disperse evenly by ultrasonication, heat to 45°C and stir and react for 10 hours, remove the solvent to obtain modified β-cyclodextrin; take allyl-β-cyclodextrin, carboxymethyl-β-cyclodextrin and modified β-cyclodextrin in a mass ratio of 1:0.6:1.5, mix evenly to obtain cyclodextrin composition;

[0044] S3: Take 20 parts of carbon black, 1 part of antioxidant RD, and 4 parts of cyclodextrin composition, stir evenly to obtain modified filler;

[0045] S4: Add 100 parts of EPDM rubber and 5 parts of methyl vinyl silicone rubber to a mixer and mix evenly. Add 4 parts of photoinitiator 2-isopropylthioxanthraquinone, 100 parts of modified filler, 10 parts of activator zinc oxide, and 2 parts of stearic acid and mix evenly. Add 25 parts of softener and mix evenly. Add 5 parts of crosslinking agent dicumyl peroxide and 3.5 parts of N-cyclohexyl-2-benzothiazole sulfenamide and mix evenly. Pass the mixture through a two-roll mill to obtain the compound.

[0046] Comparative Example 4 (using 1k molecular weight epoxy-polyethylene glycol-epoxy X-GF-0139-1k from Shaanxi Xinyan Bomei Biotechnology Co., Ltd. instead of polyethylene glycol diglycidyl ether from Shanghai Yuanye MW400, with the remaining steps consistent with Example 1): S1: Take 65 parts tung oil, 20 parts methanol, and 1 part potassium hydroxide, mix evenly, react at 70℃ for 2 hours, let stand and separate the liquid, wash until neutral, remove water by rotary evaporation to obtain methyl tungate; take 40 parts methyl tungate and 10 parts maleic anhydride, stir evenly, heat to 88℃ under nitrogen protection and react for 2 hours, wait for the reactants to cool. The mixture was cooled to room temperature, and 200 parts of acetone were added and stirred until homogeneous. The pH was adjusted to 7 with NaOH, and the acetone was removed. Cyclohexane and water were added to remove unreacted substances. The aqueous layer was collected, and excess NaOH was added. The mixture was saponified at 75°C for 3 hours. Hydrochloric acid was added dropwise for acidification. The crude product was dissolved in ethyl acetate, and dried with NaSO4 for 12 hours. After filtration, ethyl acetate was removed to obtain tungsten triglyceride. 18 parts of tungsten triglyceride, 60 parts of epoxy-polyethylene glycol-epoxy group, 0.15 parts of triphenylphosphine, and 50 parts of isobutanol were stirred until homogeneous and refluxed at 108°C for 48 hours. The solvent was removed to obtain a softener.

[0047] S2: Add 6 parts of carboxymethyl-β-cyclodextrin to 50 parts of toluene, disperse evenly by ultrasonication, add 80 parts of terephthalic diisocyanate, heat to 70°C under nitrogen protection, stir and react for 12 hours, remove the solvent to obtain isocyanate-modified cyclodextrin, add 800 parts of water, disperse evenly by ultrasonication, heat to 45°C and stir and react for 10 hours, remove the solvent to obtain modified β-cyclodextrin; take allyl-β-cyclodextrin, carboxymethyl-β-cyclodextrin and modified β-cyclodextrin in a mass ratio of 1:0.6:1.5, mix evenly to obtain cyclodextrin composition;

[0048] S3: Mix 10 parts concentrated sulfuric acid and 25 parts concentrated nitric acid evenly, add 20 parts carbon black, heat to 130℃ and react for 0.5 h, filter, wash with water and dry, add 1 part antioxidant RD and 15 parts acetone, mix evenly, grind under high pressure for 2 min, then add 4 parts cyclodextrin composition, grind under high pressure for 5 min, dry to obtain modified filler; the grinding speed is 12000 r / min and the grinding pressure is 1.2 MPa;

[0049] S4: Add 100 parts of EPDM rubber and 5 parts of methyl vinyl silicone rubber to a mixer and mix evenly. Add 4 parts of photoinitiator 2-isopropylthioxanthraquinone, 100 parts of modified filler, 10 parts of activator zinc oxide, and 2 parts of stearic acid and mix evenly. Add 25 parts of softener and mix evenly. Add 5 parts of crosslinking agent dicumyl peroxide and 3.5 parts of N-cyclohexyl-2-benzothiazole sulfenamide and mix evenly. Pass the mixture through a two-roll mill to obtain the compound.

[0050] Performance testing: Take the compound rubber prepared in Examples 1-2 and Comparative Examples 1-4; (1) Test the tensile strength according to GB / T528-2009; (2) Perform hot air aging (125℃, 168h) according to GB / T3512-2014 and test the change rate of tensile strength; (3) Test the water contact angle using a contact angle tester; see Table 1 for details;

[0051] Table 1:

[0052] Tensile strength / MPa Change rate / % Contact angle / ° Example 1 16.7 -2.0 74.9 Example 2 16.5 -2.1 75.5 Example 3 16.4 -2.0 75.0 Comparative Example 1 15.1 -7.6 86.2 Comparative Example 2 15.6 -5.2 78.8 Comparative Example 3 14.2 -8.9 82.0 Comparative Example 4 14.8 -4.4 73.5 surface

[0053] Conclusions: Comparative Example 1, using paraffin oil as a softener, showed a decrease in mechanical properties and a significant reduction in hydrophilicity due to structural changes; Comparative Example 2, using modified β-cyclodextrin instead of cyclodextrin, exhibited significantly inferior performance compared to the examples; Comparative Example 3, omitting the antioxidant, carbon black, and cyclodextrin composition, resulted in performance degradation due to compatibility and migration issues; Comparative Example 4, replacing MW400 polyethylene glycol diglycidyl ether with 1k molecular weight epoxy-polyethylene glycol-epoxy groups, improved hydrophilicity but decreased compatibility with the rubber matrix, leading to overall performance degradation; In summary, the compound prepared by this invention exhibits good mechanical properties, excellent anti-aging ability, and high hydrophilicity.

[0054] 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 foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a compounded rubber based on industrial printing rollers, characterized in that: Includes the following steps: By weight, 90-100 parts of EPDM rubber and 5-10 parts of methyl vinyl silicone rubber are added to a Banbury mixer and mixed. Then, 2-4 parts of photoinitiator, 90-100 parts of filler, 10-12 parts of activator, and 2-5 parts of stearic acid are added and mixed. Next, 20-25 parts of softener are added and mixed. Finally, 5-8 parts of crosslinking agent and 3-4 parts of accelerator are added and mixed until homogeneous. The mixture is then passed through a two-roll mill to obtain a compound. The softener is a hyperbranched tung oil softener. The preparation method of the hyperbranched tung oil softener includes the following steps: tung oil, methanol, and potassium hydroxide are mixed evenly and reacted at 60-70°C. After 1-2 hours of standing, separate the liquid into layers, wash until neutral, remove water, and obtain methyl tungate. Take methyl tungate and maleic anhydride, stir evenly, and heat to 85-90℃ under nitrogen protection for 2-3 hours. After the reactants cool to room temperature, add acetone and stir evenly. Adjust the pH to 7, remove the acetone, and remove unreacted substances. Take the aqueous layer, add excess NaOH for saponification, add hydrochloric acid dropwise for acidification, and then treat to obtain tung-matriic acid. By mass, mix 15-20 parts of tung-matriic acid, 20-25 parts of polyethylene glycol diglycidyl ether, 0.1-0.2 parts of triphenylphosphine, and 40-50 parts of isobutanol and stir. The mixture is refluxed for 45-55 hours to remove the solvent, yielding a hyperbranched tung oil softener. The polyethylene glycol diglycidyl ether has a molecular weight of 400. The filler is modified carbon black. The modified filler is prepared as follows: 10-12 parts by mass of concentrated sulfuric acid and 20-30 parts by mass of concentrated nitric acid are mixed evenly, 15-20 parts by mass of carbon black are added, and the mixture is heated to 120-130℃ for 0.5-1 hours. The mixture is then filtered, washed with water, and dried. 1-1.5 parts by mass of antioxidant RD and 10-15 parts by mass of acetone are added, mixed evenly, and ground under high pressure for 2-5 minutes. 4-6 parts by mass of cyclodextrin composition are added, and the mixture is ground under high pressure for 2-5 minutes. After 5 minutes of drying, the modified filler is obtained; the grinding speed is 12000 r / min and the grinding pressure is 1.2 MPa; the cyclodextrin composition includes allyl-β-cyclodextrin, carboxymethyl-β-cyclodextrin, and modified β-cyclodextrin in a mass ratio of 1:(0.5~0.8):(1~2); the modified β-cyclodextrin is first isocyanated with terephthalic diisocyanate, and then modified β-cyclodextrin is obtained by the reaction of isocyanate and water; the raw materials include, by mass parts: 5~10 parts of carboxymethyl-β-cyclodextrin, 50~80 parts of terephthalic diisocyanate, and 500~800 parts of water.

2. The method for preparing a compound rubber based on industrial printing rollers according to claim 1, characterized in that: The methyl tung oil comprises the following raw materials, by mass: 60-70 parts tung oil, 15-20 parts methanol, and 1-2 parts potassium hydroxide.

3. The method for preparing a compound rubber based on industrial printing rollers according to claim 1, characterized in that: The tung oil triacid comprises the following raw materials, by mass: 35-45 parts methyl tungate and 8-12 parts maleic anhydride.

4. The method for preparing a compound rubber based on industrial printing rollers according to claim 1, characterized in that: The preparation of the modified β-cyclodextrin includes the following steps: Carboxymethyl-β-cyclodextrin was added to toluene and ultrasonically dispersed until uniform. Excess terephthalic diisocyanate was added, and the mixture was heated to 70-80°C under nitrogen protection and stirred for 10-15 hours. The solvent was removed to obtain isocyanate-modified cyclodextrin. Excess water was added, and the mixture was ultrasonically dispersed until uniform. The mixture was heated to 40-50°C and stirred for 8-12 hours. The solvent was removed to obtain modified β-cyclodextrin.

5. The compound prepared by the method for preparing a compound based on an industrial printing roller according to any one of claims 1 to 4.