Production method of seed glue for styrene-butadiene latex

Abstract

The invention discloses a production method of seed glue for styrene-butadiene latex, and relates to the technical field of preparation of seed glue, and the production method comprises the following steps: preparing a monomer mixture, a premix mixture, an emulsifier mixture and an initiator mixture according to a formula proportion; transferring the prepared backing material into a reaction kettle, introducing nitrogen into the reaction kettle for 5 minutes to replace air, keeping an emptying valve to be opened, and starting a stirrer; opening a steam valve at the bottom of the reaction kettle and a jacket steam valve, synchronously heating until the kettle temperature and the jacket water temperature reach 84 + / -1 DEG C, and simultaneously finishing the preparation of an ammonium persulfate solution; dropwise adding styrene, manually controlling dropwise adding of dodecyl mercaptan, and continuously polymerizing for 3 hours; and after the monomer is dropwise added, preserving heat, cooling, replenishing the defoaming agent, sampling, detecting to be qualified, and transferring to obtain the seed glue for styrene-butadiene. By optimizing the formula proportion of the styrene, the surfactant, the sodium bicarbonate, the ammonium persulfate and the lauryl mercaptan required by synthesis and related process conditions, the energy consumption is reduced, the cost is reduced, and the effect is improved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of seed glue and particularly relates to a production method of seed glue for butadiene styrene latex. BACKGROUND

[0002] Seed polymerization is a kind of emulsion polymerization in which pre-synthesized latex particles are used as seeds, the seeds are used as polymerization reaction places, monomers adsorbed by the seeds are polymerized, and core-shell type phase particles with the seeds as cores and the monomers as shells are generated. The latex with monodispersity can be prepared by using the seed polymerization of the emulsion method, and the particle size is uniform. The existing patent CN1891728A synthesizes a novel carboxyl butadiene styrene latex by using the seed emulsion polymerization method. However, as core raw materials for producing butadiene styrene latex, the cost of the butadiene styrene seed latex directly influences the competitiveness of products. In order to save energy and reduce consumption, it is urgent to provide a more superior production method of seed glue for butadiene styrene latex. SUMMARY

[0003] The application aims at the defects and deficiencies of the prior art, and provides a production method of seed glue for butadiene styrene latex. By optimizing the formula proportion of required raw materials styrene, a surfactant, sodium bicarbonate, ammonium persulfate and dodecyl mercaptan and related process conditions, energy consumption is reduced, and cost is reduced and efficiency is increased.

[0004] In order to achieve the above-mentioned purpose, the following technical scheme is adopted in the application: the operation steps are as follows: Step one, preparation of base materials: The monomer mixture, the premixed mixture, the emulsifier mixture and the initiator mixture are prepared according to the formula proportion; Step two, pretreatment of the reaction kettle: After the base materials prepared in step one are transferred into the reaction kettle, nitrogen is introduced into the reaction kettle for 5 minutes to replace air, the emptying valve is kept open, and the stirrer is started; Step three, temperature rising and initiator preparation: The bottom steam valve and the jacket water steam valve of the reaction kettle are opened, the kettle temperature and the jacket water temperature are simultaneously heated to 84+ / -1 DEG C, and the ammonium persulfate solution is prepared at the same time; Step four, dropping and polymerization: Under the condition of 84+ / -1 DEG C, styrene is dropped, and dodecyl mercaptan is manually controlled to be dropped, and the polymerization is continuously carried out for 3 hours; during the polymerization process, the jacket water temperature is controlled at 50-60 DEG C according to the heat release after feeding for 4-5 minutes; Step five, temperature keeping and post-treatment: After the monomer dropping is completed, the temperature is kept at 84+ / -1 DEG C for 2 hours; after the temperature keeping is completed, the temperature is lowered to 50 DEG C, the defoaming agent is supplemented according to the foam condition, the seed glue for butadiene styrene is obtained after sampling detection is qualified and the material is transferred.

[0005] Further, the monomer mixture consists of styrene and dodecyl mercaptan.

[0006] Further, the premix mixture consists of sodium bicarbonate and soft water.

[0007] Further, the emulsifier mixture consists of surfactant (Disponils Ls103 type emulsifier) and soft water.

[0008] Further, the initiator mixture consists of ammonium persulfate and soft water.

[0009] Further, the stirring speed of the stirrer in step two is 80% of the maximum stirring speed thereof.

[0010] Further, in step four, the styrene is added dropwise at a flow rate of 4666.7 kg / h.

[0011] Further, in step four, the dodecyl mercaptan is added dropwise manually at a flow rate of 56.7 kg / h.

[0012] Further, the mass ratio of the styrene, surfactant, sodium bicarbonate, ammonium persulfate, and dodecyl mercaptan is 100:38.21-38.25:0.107:0.214:1.071-1.339.

[0013] Further, the prepared seed glue has the performance indexes of solid content 30.04%-32.13%, pH value 7.07-7.44, particle size 39.86-47.02 nm, and PDI 0.096-0.183.

[0014] Compared with the prior art, the beneficial effects of the present application are: 1. Cost reduction: The present application realizes the self-production of seed glue for butadiene styrene, replacing the monthly demand of 60 tons of purchased products. According to the purchase unit price, the production cost can be reduced by tens of millions of yuan per year, significantly improving the market competitiveness of butadiene styrene latex products. 2. Stable performance: Through formula optimization and precise process control, the prepared seed glue has narrow particle size distribution (PDI 0.096-0.183) and stable solid content (30.04%-32.13%), which can ensure the stability of subsequent butadiene styrene latex production, and further improve the waterproof, weather-resistant and printing performance of high-grade white card base paper. 3. Industrialization adaptation: The implementation examples from 8 kg to 50 t industrial production show that the process of the present application is stable and has strong repeatability, which can be directly adapted to the existing 100,000 tons / year butadiene styrene latex production line without large-scale equipment modification, and is easy to popularize and apply. 4. Process optimization: The determined polymerization temperature (84±1℃), stirring speed (80% of the maximum speed), holding time (2h) and nitrogen replacement (5min) parameters can effectively improve polymerization efficiency, reduce side reactions, and reduce energy consumption and raw material loss. Attached Figure Description

[0015] Figure 1 This is a data table showing the test results of styrene-butadiene seed gum in Examples 1-4 and Comparative Examples 1-2. Detailed Implementation

[0016] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. The preferred embodiments described are only examples. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] like Figure 1 As shown, the specific implementation adopts the following technical solution: Its operation steps are as follows: Step 1: Preparation of base ingredients: The monomer mixture, premix, emulsifier mixture, and initiator mixture are prepared according to the formula ratio; the monomer mixture consists of styrene and dodecyl mercaptan, the premix consists of sodium bicarbonate and soft water, the emulsifier mixture consists of Disponils Ls103 type emulsifier and soft water, and the initiator mixture consists of ammonium persulfate and soft water. Step 2: Pretreatment of the reactor: After transferring the prepared base material from step one into the reactor, purge the reactor with nitrogen for 5 minutes to replace the air, keep the vent valve open, start the agitator and set the stirring speed to 80%; Step 3: Heating and Initiator Preparation Open the steam valve at the bottom of the reactor and the steam valve in the jacket, and heat simultaneously until the reactor temperature and the jacket water temperature both reach 84±1℃, while simultaneously preparing the ammonium persulfate solution; Step 4, Dropping and Polymerization: Styrene was added dropwise at a flow rate of 4666.7 kg / h at 84±1℃, and dodecyl mercaptan was added dropwise manually at a flow rate of 56.7 kg / h, and polymerization was continued for 3 hours. During the polymerization process, the jacket water temperature was controlled at 50-60℃ 4-5 minutes after feeding, depending on the exothermic situation. Step 5: Insulation and Post-treatment After the monomer is added, the mixture is kept at 84±1℃ for 2 hours. After the insulation is completed, the temperature is lowered to 50℃, and defoamer is added according to the foam situation. After the sample is tested and found to be qualified, the material is transferred to obtain styrene-butadiene seed rubber. Example 1:

[0018] This example carries out 8 kg seed glue laboratory preparation, the specific steps are as follows: Step one, raw material configuration: styrene 2240g, dodecyl mercaptan 24g, sodium bicarbonate 2.4g, Disponils Ls103 type emulsifier 856g, ammonium persulfate 4.8g, soft water 4872.8g; Configure monomer mixture, premix mixture, emulsifier mixture and initiator mixture respectively; Step two, reactor pretreatment: the above mixture is transferred into a 50L laboratory reactor, nitrogen is introduced for 5min to replace air, the stirrer is started, and the stirring speed is set to 80%; Step three, temperature rise: turn on the heating device, and make the kettle temperature and the jacket water temperature rise to 84℃; Step four, polymerization drop: drop styrene at a rate of 1.24kg / h, and drop dodecyl mercaptan at a rate of 0.013kg / h, for 3h; After 5min of feeding, the jacket water temperature is reduced to 55℃, and the kettle temperature is maintained at 84℃; Step five, heat preservation and post-treatment: after 2h of heat preservation, the temperature is reduced to 50℃, and the sample is detected to obtain a butadiene styrene seed glue (product A) with solid content of 32.13%, pH 7.07, particle size 47.02nm, and PDI 0.096. Example 2:

[0019] This example carries out 8 kg seed glue laboratory preparation, which is different from example 1 in that the amount of dodecyl mercaptan is adjusted to 30g, and the amounts of the remaining raw materials are consistent with example 1; Production steps: same as example 1, the butadiene styrene seed glue prepared has solid content of 30.96%, pH 7.18, particle size of 39.86nm, and PDI of 0.101 (product B). Example 3:

[0020] This example carries out 35t seed glue pilot production, the specific steps are as follows: Step one, raw material configuration: styrene 9800kg, dodecyl mercaptan 105kg, sodium bicarbonate 10.5kg, Disponils Ls103 type emulsifier 3745kg, ammonium persulfate 21kg, soft water 21318.5kg; Step two, use 35m³ reactor, nitrogen replacement for 5min, stirring speed 80%, temperature rise to 84℃; Styrene drop rate 4666.7kg / h, dodecyl mercaptan drop rate 56.7kg / h, polymerization 3h; After 2h of heat preservation, the temperature is reduced to 50℃, and the material is transferred after adding defoaming agent, to obtain a butadiene styrene seed glue (product C) with solid content of 30.39%, pH 7.44, particle size of 46.28nm, and PDI of 0.183; Example 4:

[0021] The embodiment carries out 50 tons of seed glue industrial production, and the specific steps are as follows: Step one, raw material configuration: 14000kg of styrene, 187.5kg of dodecyl mercaptan, 15kg of sodium bicarbonate, 5350kg of Disponils Ls103 emulsifier, 30kg of ammonium persulfate, 30455kg of soft water; Step two, using a 50m³ industrial reaction kettle, 1301 tank configuration initiator solution (805kg soft water+30kg ammonium persulfate, stirring for 60s); after the bottom material is transferred into the 1402 reaction kettle, nitrogen is replaced for 5min, the stirring is started (80%), and the temperature is raised to 84℃; the monomer is added according to the set flow, and the polymerization is carried out for 3h; after the temperature is kept for 2h, the temperature is lowered to 50℃, the defoaming agent is added according to the foam, and then the material is transferred, to obtain the seed glue for butadiene styrene (product D) with solid content of 30.04%, pH of 7.39, particle size of 43.00nm and PDI of 0.171.

[0022] The above four embodiments and two comparative examples (purchased seed glue) are compared in performance, and the results are shown in Figure 1 The figure shows that the seed glue prepared by the application (examples 1-4) is equivalent to the purchased seed glue (comparative examples 1-2) in solid content, pH value, particle size and PDI, and the PDI of examples 1 and 2 is lower (0.096, 0.101), which indicates that the particle size distribution is narrower, and meets the performance requirements of seed glue for butadiene styrene latex production.

[0023] Compared with the prior art, the application has the following advantages: 1. Cost reduction: the application realizes the self-production of seed glue for butadiene styrene, replaces the monthly demand of 60 tons of purchased products, and reduces the production cost by hundreds of millions of yuan per year according to the purchase unit price, which significantly improves the market competitiveness of butadiene styrene latex products; 2. Stable performance: through formula optimization and process precise control, the prepared seed glue has narrow particle size distribution (PDI 0.096-0.183) and stable solid content (30.04%-32.13%), which can guarantee the stability of subsequent butadiene styrene latex production, and further improve the waterproof, weather resistance and printing performance of high-grade white card base paper; 3. Industrialization adaptation: the verification of the examples from 8kg to 50t industrial production shows that the method and process of the application are stable and have strong repeatability, which can be directly adapted to the existing 100000 tons / year butadiene styrene latex production line without large-scale equipment modification, and is easy to popularize and apply; 4. Process optimization: the determined parameters such as polymerization temperature (84±1℃), stirring speed (80% of maximum speed), holding time (2h) and nitrogen replacement (5min) can effectively improve the polymerization efficiency, reduce the occurrence of side reactions, and reduce energy consumption and raw material loss.

[0024] For those skilled in the art, the technical solutions recorded in the foregoing embodiments can be modified, and equivalent replacement of part of the technical features can be made, and any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A process for the production of seed gum for use in styrene butadiene latex, characterized by: Its operation steps are as follows: Step (one), the preparation of the base material: According to the formula, the monomer mixture, the premix mixture, the emulsifier mixture and the initiator mixture are configured; Step (two), the pre-treatment of the reactor: After the base material configured in step (one) is transferred into the reactor, nitrogen is introduced into the reactor for 5 minutes to replace the air, the exhaust valve is kept open, and the stirrer is started; Step (three), temperature rising and initiator configuration: Open the bottom steam valve and jacket water steam valve of the reactor, heat synchronously to 84±1℃, and complete the configuration of ammonium persulfate solution at the same time; Step (four), dropping and polymerization: Under the condition of 84±1℃, drop the styrene, and manually control the dropping of dodecyl mercaptan, and continue to polymerize for 3h; during the polymerization process, the jacket water temperature is controlled at 50-60℃ according to the heat release after feeding for 4-5min; Step (five), heat preservation and post-treatment: After the monomer dropping is completed, heat preservation is carried out at 84±1℃ for 2h; after heat preservation, the temperature is lowered to 50℃, defoaming agent is added according to the foam situation, and the sample is detected to be qualified, then the material is transferred, and the seed rubber for butadiene styrene is obtained.

2. A process for the production of seed gum for use in styrene butadiene latex as claimed in claim 1, wherein: The monomer mixture is composed of styrene and dodecyl mercaptan.

3. A process for the production of seed gum for use in styrene butadiene latex as claimed in claim 1, wherein: The premix mixture is composed of sodium bicarbonate and soft water.

4. A process for the production of seed gum for use in styrene butadiene latex as claimed in claim 1, wherein: The emulsifier mixture is composed of surfactant and soft water.

5. A process for the production of seed gum for use in styrene butadiene latex as claimed in claim 1, wherein: The initiator mixture is composed of ammonium persulfate and soft water.

6. A process for the production of seed gum for use in styrene butadiene latex as claimed in claim 1, wherein: The stirring speed of the stirrer in step (two) is 80% of the maximum stirring speed.

7. A process for the production of seed gum for use in styrene butadiene latex as claimed in claim 1, wherein: In step (four), the styrene is dropped at a flow rate of 4666.7kg / h.

8. A process for the production of seed gum for use in styrene butadiene latex as claimed in claim 1, wherein: In step (four), the dodecyl mercaptan is manually controlled to be dropped at a flow rate of 56.7kg / h.

9. A process for the production of seed gum for use in styrene butadiene latex as claimed in any one of claims 1 to 8, characterized in that: The mass ratio of styrene, surfactant, sodium bicarbonate, ammonium persulfate and dodecyl mercaptan is 100:38.21-38.25:0.107:0.214:1.071-1.339.

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