Emulsion type grafted chloroprene rubber and preparation method thereof

Abstract

The invention provides application of a methyl methacrylate monomer and a butyl acrylate monomer as composite grafting monomers to improvement of grafting efficiency in preparation of emulsion type grafted chloroprene rubber from chloroprene monomers. According to the environment-friendly high-grafting-efficiency chloroprene rubber provided by the invention, through composite grafting monomer type selection, initiation-regulation system collaborative design and process optimization, double improvement of grafting efficiency and environmental friendliness is realized. MMA and BA are selected as composite grafting monomers, so that the adhesive property and the toughness are considered; a potassium persulfate and methyl ether sulfinic acid low-temperature redox initiation system is adopted, so that the reaction energy consumption is reduced, and the initiation efficiency is improved; then, a dispersant naphthalene sulfonic acid formaldehyde condensate sodium salt is introduced to accurately regulate and control the reaction process, and side reaction is inhibited; a non-sulfur regulator is further matched to improve the storage stability, solvent-free environment-friendly production is realized by taking water as a medium in the whole process, and the product can be directly used for preparing a water-based adhesive or solid rubber and is suitable for multiple fields of shoe materials, automobiles, buildings, industrial sealing and the like.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of rubber modification, and relates to application of methyl methacrylate monomers and butyl acrylate monomers as composite grafting monomers in preparation of emulsion type grafted chloroprene rubber from chlorobutadiene monomers to improve grafting efficiency, an emulsion type grafted chloroprene rubber and a preparation method thereof, in particular to an emulsion type grafted chloroprene rubber and a preparation method thereof. BACKGROUND

[0002] Chloroprene rubber (CR) has excellent weather resistance, oil resistance, mechanical properties and bonding properties, and is widely used in adhesive, sealing material and other fields. However, the traditional chloroprene rubber has problems of insufficient bonding strength to polar substrates, limited heat resistance and easy scorching in the processing process, and needs to be modified by grafting to optimize the performance.

[0003] However, the preparation of the existing grafted chloroprene rubber mostly adopts a solvent polymerization method, and toluene, acetone and the like are used as solvents, which has problems of high VOC emission, serious environmental pollution and high solvent recovery cost; and some emulsion grafting processes have defects of low grafting efficiency (usually 30-40%), insufficient monomer conversion rate and large product performance fluctuation. In addition, the traditional initiation system needs to be reacted at a high temperature, which has high energy consumption and is easy to cause side reactions; and the regulation and control system lacks precise control, which is easy to cause over-polymerization or gelation, thereby limiting the industrial application of the product.

[0004] Therefore, how to develop a more suitable grafted chloroprene rubber and a preparation method thereof to solve the above technical problems of the existing grafted chloroprene rubber has become one of the technical problems to be solved by many first-line researchers and research and development enterprises in the field. SUMMARY

[0005] Therefore, the technical problem to be solved by the application is to provide application of methyl methacrylate monomers and butyl acrylate monomers as composite grafting monomers in preparation of emulsion type grafted chloroprene rubber from chlorobutadiene monomers to improve grafting efficiency, an emulsion type grafted chloroprene rubber and a preparation method thereof, in particular an emulsion type grafted chloroprene rubber and a preparation method thereof. The emulsion type grafted chloroprene rubber prepared by the application has the characteristics of environmental protection, low VOC, high grafting efficiency and stable performance, and has the advantages of simple process, mild conditions and strong operability, and is more suitable for popularization and application in industrial production.

[0006] The application provides application of methyl methacrylate monomers and butyl acrylate monomers as composite grafting monomers in preparation of emulsion type grafted chloroprene rubber from chlorobutadiene monomers to improve grafting efficiency.

[0007] Preferably, the mass ratio of the methyl methacrylate monomers to the chlorobutadiene monomers is (12-25): 100.

[0008] The mass ratio of the butyl acrylate monomer to the chlorobutadiene monomer is (5-15): 100;

[0009] The application also includes the potassium persulfate and methyl ether sulfinate redox initiation system combined with the composite grafting monomer.

[0010] The mass ratio of the methyl methacrylate monomer to the butyl acrylate monomer is (1-3): 1.

[0011] Preferably, the application also includes the potassium persulfate and methyl ether sulfinate redox initiation system combined with the naphthalene sulfonate formaldehyde condensate sodium salt to form an initiation-regulation system, which is applied in combination with the composite grafting monomer.

[0012] The mass ratio of the naphthalene sulfonate formaldehyde condensate sodium salt to the chlorobutadiene monomer is (0.05-0.3): 100.

[0013] The application direction also includes improving the monomer conversion rate.

[0014] The grafted chlorobutyl rubber is specifically a non-sulfur grafted system chlorobutyl rubber.

[0015] The application provides an emulsion type grafted chlorobutyl rubber, which comprises, by mass fraction of raw materials:

[0016] chlorobutadiene monomer 100 parts by weight;

[0017] methyl methacrylate monomer 12-25 parts by weight;

[0018] butyl acrylate monomer 5-15 parts by weight;

[0019] potassium persulfate 0.3-0.6 parts by weight;

[0020] methyl ether sulfinate 0.03-0.1 parts by weight;

[0021] naphthalene sulfonate formaldehyde condensate sodium salt 0.05-0.3 parts by weight;

[0022] SDBS 0.4-0.6 parts by weight;

[0023] OP-10 0.4-0.6 parts by weight;

[0024] n-dodecyl mercaptan 0.5-1.5 parts by weight;

[0025] disinfected pine rosin 3-5 parts by weight;

[0026] NaOH 0.6-1 parts by weight;

[0027] water 90-110 parts by weight.

[0028] Preferably, the mass ratio of the methyl methacrylate monomer and the butyl acrylate monomer is (1-3):1;

[0029] The mass ratio of the potassium persulfate and the methyl ether sulfinate is (8-10):1.

[0030] The emulsion type grafted neoprene rubber is a high grafting efficiency grafted neoprene rubber.

[0031] The emulsion type grafted neoprene rubber comprises a neoprene rubber for water-based adhesives or solid rubber.

[0032] The application provides a preparation method of the emulsion type grafted neoprene rubber.

[0033] 1) SDBS, OP-10, disulfated rosin, NaOH, naphthalene sulfonate formaldehyde condensate sodium salt and water are heated and mixed, and after dissolution, a water phase mixture is obtained;

[0034] Under a protective atmosphere, chlorobutadiene monomers and n-dodecanethiol are mixed to obtain oil phase one;

[0035] Under a protective atmosphere, methyl methacrylate monomers, butyl acrylate monomers and n-dodecanethiol are mixed to obtain oil phase two;

[0036] 2) The water phase mixture and the oil phase one obtained in the above step are mixed, and then potassium persulfate and methyl ether sulfinate are added and mixed to carry out a polymerization reaction; when the reaction system reaches a first specific gravity, oil phase two is added and maintained at a first temperature; after the addition is completed, the temperature is increased to a second temperature for continuous reaction, and then the reaction is terminated; then, after acidification and demulsification, a grafted neoprene rubber is obtained.

[0037] Preferably, the temperature of the heating and mixing is 80-90 DEG C.

[0038] The temperature of the polymerization reaction is 10-25 DEG C.

[0039] The first specific gravity is 1.060-1.070.

[0040] Preferably, the oil phase two is added in the form of dropwise addition.

[0041] The time for adding the oil phase two is 1.8-2.5 h.

[0042] The first temperature is 50-65 DEG C.

[0043] Preferably, the second temperature is 55-70 DEG C.

[0044] The time for the continuous reaction is 2-3 h.

[0045] The termination reaction includes adding N, N-diethylhydroxylamine and N-isopropylhydroxylamine to terminate the reaction.

[0046] Preferably, the acid demulsification comprises acid demulsification after cooling.

[0047] The acid demulsification is specifically acid demulsification by adding an acetic acid aqueous solution.

[0048] The mass concentration of the acetic acid aqueous solution is 27.5% to 29.5%.

[0049] After the acid demulsification, one or more of cooling, drum film forming, water washing, dewatering and drying are further included.

[0050] The application provides application of methyl methacrylate monomers and butyl acrylate monomers as composite grafting monomers in preparation of emulsion type grafted neoprene rubber from chlorobutadiene monomers to improve grafting efficiency. Compared with the prior art, the application is particularly applied to methyl methacrylate monomers and butyl acrylate monomers as composite grafting monomers in preparation of emulsion type grafted neoprene rubber from chlorobutadiene monomers, so as to further improve the grafting efficiency.

[0051] The core idea of the application is that MMA (methyl methacrylate) monomers and BA (butyl acrylate) monomers are selected as composite grafting monomers, the adhesion and toughness are considered, a potassium persulfate and dimethyl sulfide sulfoxide low-temperature oxidation-reduction initiation system is adopted to reduce reaction energy consumption and improve initiation efficiency, a dispersant naphthalene formaldehyde sulfoxylate sodium salt is introduced to precisely control the reaction process and inhibit side reactions, and a non-sulfur regulator is further matched to improve storage stability, and the whole process is realized by using water as a medium to realize solvent-free and environmentally-friendly production.

[0052] The emulsion type grafted neoprene rubber and the preparation method thereof have the following advantages: environmental friendliness is significantly improved: an emulsion polymerization process is adopted, no organic solvent is added, VOC emission is reduced by more than 95%, meets the EU REACH and the VOC emission standard of China, and the operation environment is friendly; moreover, the grafting efficiency and the conversion rate are high: through the synergistic effect of the initiation-regulation system, the grafting efficiency is greater than or equal to 60%, the monomer conversion rate is greater than or equal to 96%, which is much higher than that of the traditional emulsion grafting process (the grafting efficiency is 30%-40%); meanwhile, the performance is balanced and excellent: the weather resistance and oil resistance of the neoprene rubber are retained, the bonding strength is increased by more than 40%, the heat resistance temperature is increased by 15-20 DEG C, the storage period is extended to 2-3 years, and the rubber is not easy to scorch and stick to the roller. In addition, the preparation process has strong controllability: the reaction temperature is low (50-70 DEG C), the energy consumption is low, the temperature fluctuation is less than or equal to ± 2 DEG C, the product batch stability is good, and the process is suitable for large-scale industrial production. The emulsion type grafted neoprene rubber has wide application scenarios: can be directly prepared into water-based adhesive or solid rubber, is suitable for multiple fields such as shoe materials, automobiles, buildings and industrial sealing, and has strong practicability. DETAILED DESCRIPTION

[0053] In order to further understand the present application, the preferred embodiments of the present application are described below in conjunction with examples, but it should be understood that the description is only for further illustrating the features and advantages of the present application, and is not a limitation on the claims of the present application.

[0054] All raw materials of the present application have no special limitation on the source, and can be purchased on the market or prepared according to the conventional method known to those skilled in the art.

[0055] All raw materials of the present application have no special limitation on the purity, and the analytical pure or conventional purity used in the field of grafted neoprene rubber preparation is preferably adopted.

[0056] The present application provides the application of methyl methacrylate monomer and butyl acrylate monomer as composite grafting monomers in the preparation of emulsion type grafted neoprene rubber from chlorobutadiene monomers to improve the grafting efficiency.

[0057] In the present application, the mass ratio of the methyl methacrylate monomer to the chlorobutadiene monomer is preferably (12-25):100, more preferably (15-22):100, and more preferably (18-21):100.

[0058] In the present application, the mass ratio of the butyl acrylate monomer to the chlorobutadiene monomer is preferably (5-15):100, more preferably (7-13):100, and more preferably (9-11):100.

[0059] In the present application, the application further preferably includes the application of the potassium persulfate and methyl ether sulfoxide redox initiation system in combination with the composite grafting monomers.

[0060] In the present application, the mass ratio of the methyl methacrylate monomer and the butyl acrylate monomer is preferably (1-3):1, more preferably (1.4-2.6):1, and more preferably (1.8-2.2):1.

[0061] In the present application, the application also preferably includes that the potassium persulfate and the methyl ether sulfinate redox initiation system are synergized with the naphthalene sulfonate formaldehyde condensate sodium salt to form an initiation-regulation system, and the application is combined with the composite grafting monomer.

[0062] In the present application, the mass ratio of the naphthalene sulfonate formaldehyde condensate sodium salt and the chlorobutadiene monomer is preferably (0.05-0.3):100, more preferably (0.1-0.25):100, and more preferably (0.15-0.2):100.

[0063] In the present application, the direction of the application also preferably includes improving the monomer conversion rate.

[0064] In the present application, the grafted chlorobutyl rubber is specifically preferably a non-sulfur grafting system chlorobutyl rubber.

[0065] The present application provides an emulsion type grafted chlorobutyl rubber, which comprises, by mass fraction of raw materials:

[0066] chlorobutadiene monomer 100 parts by weight;

[0067] methyl methacrylate monomer 12-25 parts by weight;

[0068] butyl acrylate monomer 5-15 parts by weight;

[0069] potassium persulfate 0.3-0.6 parts by weight;

[0070] methyl ether sulfinate 0.03-0.1 parts by weight;

[0071] naphthalene sulfonate formaldehyde condensate sodium salt 0.05-0.3 parts by weight;

[0072] SDBS 0.4-0.6 parts by weight;

[0073] OP-10 0.4-0.6 parts by weight;

[0074] n-dodecyl mercaptan 0.5-1.5 parts by weight;

[0075] disinfected pine rosin 3-5 parts by weight;

[0076] NaOH 0.6-1 parts by weight;

[0077] water 90-110 parts by weight.

[0078] In the present application, the methyl methacrylate monomer is added in an amount of 12-25 parts by weight, can be 14-21 parts by weight, can be 16-19 parts by weight, and specifically can be 12, 20 or 25 parts by weight.

[0079] In the present application, the butyl acrylate monomer is added in an amount of 5-15 parts by weight, can be 7-13 parts by weight, can be 9-11 parts by weight, and specifically can be 10 or 12 parts by weight.

[0080] In the present application, the potassium persulfate is added in an amount of 0.3-0.6 parts by weight, can be 0.35-0.55 parts by weight, can be 0.4-0.5 parts by weight, and specifically can be 0.3, 0.5 or 0.6 parts by weight.

[0081] In the present application, the methyl ether sulfinic acid is added in an amount of 0.03-0.1 parts by weight, can be 0.04-0.075 parts by weight, can be 0.05-0.065 parts by weight.

[0082] In the present application, the naphthalene sulfonic acid formaldehyde condensate sodium salt is added in an amount of 0.05-0.3 parts by weight, can be 0.1-0.25 parts by weight, can be 0.15-0.2 parts by weight.

[0083] In the present application, the SDBS is added in an amount of 0.4-0.6 parts by weight, can be 0.44-0.56 parts by weight, can be 0.48-0.52 parts by weight, and specifically can be 0.4, 0.5 or 0.6 parts by weight.

[0084] In the present application, the OP-10 is added in an amount of 0.4-0.6 parts by weight, can be 0.44-0.56 parts by weight, can be 0.48-0.52 parts by weight, and specifically can be 0.4, 0.5 or 0.6 parts by weight.

[0085] In the present application, the n-dodecyl mercaptan is added in an amount of 0.5-1.5 parts by weight, can be 0.7-1.3 parts by weight, can be 0.9-1.1 parts by weight, and specifically can be 0.6, 0.8 or 1.0 parts by weight.

[0086] In the present application, the dismutation rosin is added in an amount of 3-5 parts by weight, can be 3.4-4.6 parts by weight, can be 3.8-4.2 parts by weight. Specifically, it can be 5 parts by weight.

[0087] In the present application, the NaOH (fold hundred) is added in an amount of 0.6-1 parts by weight, can be 0.65-0.95 parts by weight, can be 0.7-0.9 parts by weight. Specifically, it can be 0.8 parts by weight.

[0088] In the present application, the water is added in an amount of 90-110 parts by weight, can be 94-106 parts by weight, can be 98-102 parts by weight, and specifically can be 90, 100 or 110 parts by weight.

[0089] In the present application, the mass ratio of the methyl methacrylate monomer and the butyl acrylate monomer is preferably (1-3):1, more preferably (1.4-2.6):1, and more preferably (1.8-2.2):1.

[0090] In the present application, the mass ratio of the potassium persulfate and the methyl ether sulfinate is preferably (8-10):1, more preferably (8.4-9.6):1, and more preferably (8.8-9.2):1, and specifically can be 10:1.

[0091] In the present application, the emulsion type grafted neoprene rubber is preferably a high grafting efficiency grafted neoprene rubber.

[0092] In the present application, the emulsion type grafted neoprene rubber preferably includes a neoprene rubber used for water-based adhesives or solid rubbers.

[0093] The present application provides a preparation method of the emulsion type grafted neoprene rubber according to any one of the above-mentioned technologies, comprising the following steps:

[0094] 1) SDBS, OP-10, disulfated rosin, NaOH, naphthalene sulfonate formaldehyde condensate sodium salt and water are heated and mixed, and after dissolution, a water phase mixture is obtained;

[0095] Under a protective atmosphere, chlorobutadiene monomers and n-dodecanethiol are mixed to obtain oil phase one;

[0096] Under a protective atmosphere, methyl methacrylate monomers, butyl acrylate monomers and n-dodecanethiol are mixed to obtain oil phase two;

[0097] 2) The water phase mixture obtained in the above step and oil phase one are mixed, and then potassium persulfate and methyl ether sulfinate are added and mixed to continue the polymerization reaction, when the reaction system reaches the first specific gravity, oil phase two is added and maintained at the first temperature, after the addition is completed, the temperature is raised to the second temperature to continue the reaction, and then the reaction is terminated, and then the grafted neoprene rubber is obtained after acidification and demulsification.

[0098] First, SDBS, OP-10, disulfated rosin, NaOH, naphthalene sulfonate formaldehyde condensate sodium salt and water are heated and mixed, and after dissolution, a water phase mixture is obtained;

[0099] Under a protective atmosphere, chlorobutadiene monomers and n-dodecanethiol are mixed to obtain oil phase one;

[0100] The oil phase II is obtained by mixing methyl methacrylate monomer, butyl acrylate monomer and n-dodecanethiol under a protective atmosphere.

[0101] In the present application, the temperature of the heating and mixing can be 80-90℃, 82-88℃, or 84-86℃.

[0102] The water phase mixture and the oil phase I obtained in the above steps are mixed, and then potassium persulfate and dimethyl sulfoxide are added for further mixing to perform a polymerization reaction. When the reaction system reaches a first specific gravity, the oil phase II is added and maintained at a first temperature. After the addition is completed, the temperature is raised to a second temperature for further reaction, and then the reaction is terminated. After acidification and demulsification, the grafted chloroprene rubber is obtained.

[0103] In the present application, the temperature of the polymerization reaction is preferably 10-25℃, more preferably 13-22℃, and more preferably 16-19℃.

[0104] In the present application, the first specific gravity is preferably 1.060-1.070, more preferably 1.062-1.068, and more preferably 1.064-1.066, and specifically can be 1.065.

[0105] In the present application, the method of adding the oil phase II preferably includes dropwise addition.

[0106] In the present application, the time of adding the oil phase II is preferably 1.8-2.5h, more preferably 1.9-2.4h, more preferably 2.0-2.3h, and more preferably 2.1-2.2h, and specifically can be 1.8h, 2h or 2.2h.

[0107] In the present application, the first temperature is preferably 50-65℃, more preferably 53-62℃, and more preferably 56-59℃, and specifically can be 55℃, 52℃ or 58℃.

[0108] In the present application, the second temperature is preferably 55-70℃, more preferably 56-59℃, and more preferably 57-58℃. That is, the post-reaction temperature, and specifically can be 58℃, 60℃ or 65℃.

[0109] In the present application, the time of the further reaction is preferably 2-3h, more preferably 2.2-2.8h, and more preferably 2.4-2.6h. That is, the post-reaction time, and specifically can be 2h, 2.5h or 3h.

[0110] In the present application, the method of terminating the reaction preferably includes adding N,N-diethylhydroxylamine and N-isopropylhydroxylamine to terminate the reaction.

[0111] In the present application, the acidification and demulsification preferably include cooling and then acidification and demulsification.

[0112] In the present application, the acidification demulsification is particularly preferably carried out by adding an aqueous acetic acid solution.

[0113] In the present application, the mass concentration of the aqueous acetic acid solution is preferably 27.5% to 29.5%, more preferably 27.9% to 29.1%, more preferably 28.3% to 28.7, and specifically can be 28%.

[0114] In the present application, after the acidification demulsification, one or more steps of cooling drum film forming, water washing, dewatering and drying are further preferably included, and more preferably multiple steps of cooling drum film forming, water washing, dewatering and drying.

[0115] The present application is a complete and detailed overall technical solution, which better ensures the structure and composition of the emulsion type grafted neoprene rubber, and further improves the properties of the emulsion type grafted neoprene rubber. The application of the above methyl methacrylate monomer and butyl acrylate monomer as a composite grafting monomer in the preparation of emulsion type grafted neoprene rubber from chlorobutadiene monomers to improve grafting efficiency, an emulsion type grafted neoprene rubber and a preparation method thereof can specifically include the following contents:

[0116] In the composite grafting monomer of the present application, MMA improves adhesion and polarity, and BA improves toughness and yellowing resistance. When the ratio of the two is 1:1 to 3:1, the performance is optimal. If the ratio is too high or too low, the adhesion strength will decrease or the heat resistance will be insufficient.

[0117] When the weight ratio of the potassium persulfate-methyl ether sulfinate initiation system is 10:1, the low-temperature initiation efficiency is the highest. If the weight ratio is less than 10:1, the initiation is insufficient. If the weight ratio is higher than 10:1, side reactions are prone to occur.

[0118] The dosage of the dispersing agent naphthalene sulfonate formaldehyde condensate sodium salt is controlled to be 0.05-0.3 parts. If the dosage is too low, the grafting reaction cannot be effectively controlled. If the dosage is too high, the grafting reaction will be inhibited.

[0119] The dosage of the non-sulfur regulator n-dodecanethiol is 0.5-1.5 parts, which can balance the molecular weight and storage stability.

[0120] During the post-processing, the concentration of the demulsification aqueous acetic acid solution is 28%. If the concentration is too high, the product salt content will exceed the standard, and the product will discolor and turn yellow. If the concentration is too low, the demulsification will be incomplete.

[0121] The water-based adhesive prepared by the product can be directly used for bonding the upper and the sole of sports shoes. After coating, the adhesive is left to stand for 10-15 min, and then is attached and pressed at 0.3-0.5 MPa. The adhesive is cured at room temperature for 24 h, and the bonding strength reaches 3.7-4.1 MPa, which meets the use requirements of the shoe material industry. When the adhesive is used for bonding the instrument panel and the plastic framework of the automobile interior, the adhesive can withstand high-temperature aging at 80℃ for 1000 h, and the bonding performance does not decrease obviously. The adhesive is environmentally friendly and low in odor, and meets the standards for automobile interiors.

[0122] The emulsion type grafted neoprene provided by the application introduces MMA (methyl methacrylate) and BA (butyl acrylate) composite monomers in the neoprene emulsion, grafts the functional monomers to the neoprene (CR) main chain, retains the characteristic advantages of CR, realizes the upgrading of key performances such as adhesion and heat resistance, and has become the core material in the fields of adhesives, sealing materials and the like. After grafting the composite monomers, the adhesion strength to polar substrates such as PVC, artificial leather and metal is improved, the initial adhesion and holding adhesion are significantly improved. The heat resistance is enhanced: the main chain crystallinity is destroyed by the branched chain, and the heat distortion temperature is increased. The processing and storage stability is optimized: the storage period of the non-sulfur grafting system is extended to 2-3 years, and the system is not easy to scorch; the anti-sticking roller property of the emulsion grafting product is improved, the processing window is wider, and the compatibility is improved: the compatibility with PVC, resin and filler is improved, and the product delamination and brittle fracture problems are reduced. The environmental protection property is strengthened: the VOCs emission of the emulsion grafting process is extremely low, and the green production standard is met.

[0123] The above content of the application provides the application of methyl methacrylate monomers and butyl acrylate monomers as composite grafting monomers in the preparation of emulsion type grafted neoprene from neoprene monomers to improve grafting efficiency, an emulsion type grafted neoprene and a preparation method thereof, and particularly relates to an emulsion type grafted neoprene and a preparation method thereof. The application particularly applies methyl methacrylate monomers and butyl acrylate monomers as composite grafting monomers in the preparation of emulsion type grafted neoprene from neoprene monomers, so as to further improve the grafting efficiency. Meanwhile, the application provides an environmentally friendly high grafting efficiency neoprene and a preparation method thereof, which realizes the dual improvement of grafting efficiency and environmental protection through the selection of composite grafting monomers, the synergistic design of initiation-regulation system and process optimization.

[0124] The core idea of the application is that MMA (methyl methacrylate) monomers and BA (butyl acrylate) monomers are selected as composite grafting monomers, the adhesion and toughness are considered; a potassium persulfate and dimethyl sulfide sulfoxide low-temperature oxidation-reduction initiation system is used to reduce the reaction energy consumption and improve the initiation efficiency; a dispersant naphthalene formaldehyde condensate sodium salt is further introduced to accurately control the reaction process and inhibit the side reaction; and a non-sulfur regulator is further matched to improve the storage stability, and the whole process is realized by using water as a medium to realize solvent-free and environmentally friendly production.

[0125] The emulsion type grafted neoprene rubber and the preparation method thereof have the following advantages: environmental friendliness is significantly improved: an emulsion polymerization process is adopted, no organic solvent is added, VOC emission is reduced by more than 95%, meets the EU REACH and the VOC emission standard of China, and the operation environment is friendly; moreover, the grafting efficiency and the conversion rate are high: through the synergistic effect of the initiation-regulation system, the grafting efficiency is greater than or equal to 60%, the monomer conversion rate is greater than or equal to 96%, which is much higher than that of the traditional emulsion grafting process (the grafting efficiency is 30% to 40%); meanwhile, the performance is balanced and excellent: the weather resistance and oil resistance of the neoprene rubber are retained, the bonding strength is increased by more than 40%, the heat resistance temperature is increased by 15-20 DEG C, the storage period is extended to 2 to 3 years, and the rubber is not easy to scorch and stick. In addition, the preparation process has strong controllability: the reaction temperature is low (50-70 DEG C), the energy consumption is low, the temperature fluctuation is less than or equal to ± 2 DEG C, the product batch stability is good, and the process is suitable for large-scale industrial production. The emulsion type grafted neoprene rubber has wide application scenarios: can be directly prepared into water-based adhesive or solid rubber, is suitable for multiple fields such as shoe materials, automobiles, buildings and industrial sealing, and has strong practicability.

[0126] In order to further illustrate the present application, the application of methyl methacrylate monomer and butyl acrylate monomer as composite grafting monomers in the preparation of emulsion type grafted neoprene rubber from chlorobutadiene monomers to improve grafting efficiency, and an emulsion type grafted neoprene rubber and a preparation method thereof are described in detail in the following examples, but it should be understood that these examples are implemented on the premise of the technical scheme of the present application, and detailed implementation modes and specific operation processes are given, which are only for further illustrating the features and advantages of the present application, but not for limiting the claims of the present application, and the protection scope of the present application is not limited to the following examples.

[0127] Example 1

[0128] Raw material formula (weight parts): chlorobutadiene monomer 100, MMA 25, BA 10, potassium persulfate 0.5, methyl ether sulfinic acid 0.05, SDBS 0.5, OP-10 0.5, n-dodecyl mercaptan 0.8, disulfated rosin 5, NaOH (100%) 0.8, dispersant naphthalene sulfonate formaldehyde condensate sodium salt 0.1, deionized water 100;

[0129] Preparation steps:

[0130] 1. Water phase preparation: 100 parts of deionized water, 0.5 parts of SDBS, 0.5 parts of OP-10, disulfated rosin 5 parts, NaOH (100%) 0.65 parts, dispersant naphthalene sulfonate formaldehyde condensate sodium salt 0.1 parts, 80 rpm stirring, mixing temperature 85 DEG C, stirring and mixing for 1 hour, then sampling analysis, qualified, cooling to ≤50 DEG C.

[0131] 2. Oil phase one preparation: nitrogen replacement for 3 times, 100 parts of chloroprene monomer, 0.7 parts of n-dodecanethiol, 100 rpm stirring for 25 min;

[0132] 3. Oil phase two preparation: nitrogen replacement for 3 times, 25 parts of MMA, 10 parts of BA, 0.1 parts of n-dodecanethiol, 100 rpm stirring for 25 min;

[0133] 4. Reaction start: add water phase and stir for 10 min, add oil phase one and stir for 15 min, then add 0.5 parts of potassium persulfate and 0.05 parts of dimethyl ether sulfinate, stir for 5 min; until the polymerization reaction starts, the polymerization temperature range is 15℃.

[0134] 5. When the specific gravity reaches 1.065, start dropping oil phase two: drop at a uniform speed within 2h, the temperature is maintained at 55℃, and the stirring speed is 160 rpm;

[0135] 6. Post-reaction: after dropping is completed, react at 60℃ for 2.5h, the second monomer conversion rate is 97.2%, and then add 0.15 parts of N,N-diethylhydroxylamine (DEHA) and N-isopropylhydroxylamine (IPHA) for termination;

[0136] 7. Post-treatment: cool to room temperature, add 28% acetic acid aqueous solution for acidification and demulsification, freeze and drum to form a film, wash the film with water for 4 times, extrude and dehydrate (water content is 8%), and then vacuum dry at -0.09 MPa and 50℃ for 5h to obtain a finished product.

[0137] Example 2

[0138] Raw material formula (parts by weight): chloroprene monomer 100, MMA 20, BA 10, potassium persulfate 0.6, dimethyl ether sulfinate 0.07, dispersant naphthalene formaldehyde condensate sodium salt 0.15, SDBS 0.6, OP-10 0.6, n-dodecanethiol 1.0, disulfated rosin 5, NaOH (100%) 0.8, deionized water 110;

[0139] Preparation steps: refer to example 1, adjust the temperature of step 5 to 58℃, the dropping time to 2.2h, the post-reaction temperature to 65℃, and the reaction time to 3h, and the monomer conversion rate is 96.8%.

[0140] Example 3

[0141] Raw material formula (parts by weight): chloroprene monomer 100, MMA 12, BA 12, potassium persulfate 0.3, dimethyl ether sulfinate 0.0375, dispersant naphthalene formaldehyde condensate sodium salt 0.08, SDBS 0.4, OP-10 0.4, n-dodecanethiol 0.6, disulfated rosin 5, NaOH (100%) 0.8, deionized water 90;

[0142] Preparation step: refer to example 1, adjust the temperature of step 5 to 52℃, drop time 1.8h, post-reaction temperature 58℃, reaction 2h, monomer conversion rate 96.5%.

[0143] Performance test, the products prepared by examples 1~3 of the present application were tested for performance, and the results are shown in table 1 below, table 1 is the performance data of the emulsion type grafted neoprene prepared by the examples of the present application.

[0144] Table 1

[0145]

[0146] The emulsion type grafted neoprene and its preparation method provided by the present application are described in detail above, specific examples are applied in this paper to explain the principles and implementation modes of the present application, the above examples are only used to help understand the method of the present application and its core idea, including the best mode, and also enable any person skilled in the art to practice the present application, including manufacturing and using any device or system, and implementing any combined method. It should be noted that for ordinary skilled persons in the art, some improvements and modifications can be made to the present application without departing from the principles of the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application. The scope of the patent protection of the present application is defined by the claims, and can include other embodiments that can be thought of by those skilled in the art. If these other embodiments have structural elements that are not different from the expression of the claims, or if they include equivalent structural elements that are not substantially different from the expression of the claims, then these other embodiments should also be included in the scope of the claims.

Claims

1. Application of methyl methacrylate monomer and butyl acrylate monomer as composite grafting monomers in improving grafting efficiency in the preparation of emulsion-type grafted chloroprene rubber from chloroprene monomer.

2. The preparation method according to claim 3, characterized in that, The mass ratio of methyl methacrylate monomer to chloroprene monomer is (12~25):100; The mass ratio of butyl acrylate monomer to chloroprene monomer is (5~15):100; The application also includes the application of a potassium persulfate and dimethyl ether sulfinic acid redox initiation system in combination with a composite grafting monomer. The mass ratio of methyl methacrylate monomer to butyl acrylate monomer is (1~3):

1.

3. The preparation method according to claim 2, characterized in that, The application also includes the use of a potassium persulfate and dimethyl ether sulfinic acid redox initiation system in synergy with sodium salt of naphthalene sulfonic acid formaldehyde condensate to form an initiation-regulation system, which is then combined with composite grafting monomers for application. The mass ratio of the sodium salt of the naphthalenesulfonic acid formaldehyde condensate to the chloroprene monomer is (0.05~0.3):100; The application also includes improving monomer conversion rate; The grafted chloroprene rubber is specifically a non-sulfur grafted chloroprene rubber system.

4. An emulsion-type grafted chloroprene rubber, characterized in that, Based on the mass fractions of raw materials, including: 100 parts by weight of chloroprene monomer; 12-25 parts by weight of methyl methacrylate monomer; 5-15 parts by weight of butyl acrylate monomer; Potassium persulfate 0.3~0.6 parts by weight; 0.03~0.1 parts by weight of dimethyl ether sulfinic acid; Sodium salt of naphthalenesulfonic acid formaldehyde condensate, 0.05~0.3 parts by weight; SDBS 0.4~0.6 parts by weight; OP-10 0.4~0.6 parts by weight; 0.5 to 1.5 parts by weight of dodecyl mercaptan; 3-5 parts by weight of disproportionated rosin; 0.6~1 parts by weight of NaOH; 90-110 parts by weight of water.

5. The emulsion-type grafted chloroprene rubber according to claim 4, characterized in that, The mass ratio of methyl methacrylate monomer to butyl acrylate monomer is (1~3):1; The mass ratio of potassium persulfate to dimethyl ether sulfinic acid is (8~10):1; The emulsion-type grafted chloroprene rubber is a grafted chloroprene rubber with high grafting efficiency; The emulsion-type grafted chloroprene rubber includes chloroprene rubber used in water-based adhesives or solid rubbers.

6. A method for preparing emulsion-type grafted chloroprene rubber as described in any one of claims 4 to 5, characterized in that, Includes the following steps: 1) SDBS, OP-10, disproportionated rosin, NaOH, sodium salt of naphthalenesulfonic acid formaldehyde condensate, and water are heated and mixed to obtain an aqueous phase mixture after dissolution; Under a protective atmosphere, chloroprene monomer and n-dodecyl mercaptan were mixed to obtain oil phase one; Under a protective atmosphere, methyl methacrylate monomer, butyl acrylate monomer and n-dodecyl mercaptan were mixed to obtain oil phase II; 2) After mixing the aqueous phase mixture obtained in the above steps with oil phase one, potassium persulfate and dimethyl ether sulfinic acid are added and mixed to carry out the polymerization reaction. When the reaction system reaches the first specific gravity, oil phase two is added and the first temperature is maintained. After the addition is completed, the temperature is raised to the second temperature and the reaction is continued. Then the reaction is terminated. After acidification and demulsification, grafted chloroprene rubber is obtained.

7. The preparation method according to claim 6, characterized in that, The temperature for heating and mixing is 80~90℃; The polymerization reaction is carried out at a temperature of 10~25℃; The first specific gravity is 1.060~1.

070.

8. The preparation method according to claim 6, characterized in that, The method of adding oil phase II includes dropwise addition; The time for adding oil phase II is 1.8~2.5h; The first temperature is 50~65℃.

9. The preparation method according to claim 6, characterized in that, The second temperature is 55~70℃; The continued reaction time is 2-3 hours; The reaction termination method includes adding N,N-diethylhydroxylamine and N-isopropylhydroxylamine to terminate the reaction.

10. The preparation method according to claim 6, characterized in that, The acidification demulsification includes cooling followed by acidification demulsification. The acidification demulsification specifically involves adding an aqueous acetic acid solution for acidification demulsification. The mass concentration of the acetic acid aqueous solution is 27.5%~29.5%; The process after acidification and demulsification also includes one or more steps such as cooling drum film formation, water washing, dehydration, and drying.

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