Preparation method and application of polybutadiene latex emulsion and preparation method of MBS powder

Abstract

The invention discloses a preparation method of a polybutadiene latex emulsion, which comprises the following steps: adding 1, 3-butadiene, an oxidant, a reducing agent, an accelerant, an emulsifier and deionized water into a reaction kettle, and heating the reaction kettle for reaction; raising the temperature, adding an unsaturated acid monomer solution, and continuously reacting; and cooling, adding a neutralizer into the reaction kettle, continuously stirring, cooling and discharging to obtain the polybutadiene latex emulsion. The polybutadiene latex emulsion provided by the invention can be used as an MBS plasticizer and can be used for preparing MBS powder. According to the method, the unsaturated acid monomer is added in the reaction process, so that large-particle-size latex can be synthesized, and meanwhile, the grafting rate can be increased by adding the transition layer; the added neutralizer is mainly used for neutralizing acidic groups on molecular chains, and the situation that the acidic groups are left in particles to affect aging properties such as heat resistance and yellowing resistance of the product is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of polymer emulsion preparation, in particular to a preparation method of polybutadiene latex emulsion and application thereof and a preparation method of MBS powder. Background Art

[0002] MBS resin is an important polymer material, widely used in coatings, adhesives, sealants and other fields. The preparation of MBS resin mainly depends on the synthesis of polybutadiene latex. Polybutadiene latex is a polymer emulsion prepared by emulsion polymerization of polybutadiene molecules in water. During the preparation process, the particle size and particle size distribution of polybutadiene latex can be controlled by adjusting the polymerization conditions, such as reaction temperature, reaction time, monomer concentration, etc.

[0003] There are two main processes for preparing MBS resin: one is the agglomeration process, that is, the first step is to synthesize a small-particle polybutadiene latex (100-200nm), and the second step is to add an agglomerating agent at room temperature and mix evenly, and then the emulsion particle size increases slowly and irregularly under physical action, and then the MBS resin is obtained through grafting and flocculation. Although this method is time-consuming, the process steps are complicated, slag is easily discharged during agglomeration, the particle size distribution is uncontrollable, and the obtained MBS resin particle size distribution is wide. For example, Chinese patent CN104327281A discloses a method for preparing a unimodal polybutadiene latex. The polymer agglomerating agent used in this patent is an acrylic emulsion. The emulsion particle size is increased by adding an agglomerating agent to the small-particle polybutadiene latex. The average particle size after agglomeration is 300-600nm, but the emulsion particle size distribution obtained by this method is as wide as 200-1000nm.

[0004] Another method is to directly synthesize large-particle polybutadiene latex by reducing auxiliary agents such as emulsifiers, and obtain MBS resin through grafting and flocculation. This method does not need to add agglomerating agents to expand the diameter, and the process flow is simple, but the polymerization reaction time is long and usually increases by more than 2 times, and the production efficiency is low. For example, the influence of polymerization conditions on the particle size of styrene-butadiene latex in the literature of Qu Yin et al. [Elastomer, 2012, 22 (5), 46-48], the polymerization time is more than 24h.

[0005] Although the existing MBS resin preparation process can prepare polybutadiene latex with a certain particle size and particle size distribution, there are still some problems. First, the existing process steps are complicated, the operation is difficult, and a large amount of manpower and material resources are consumed. Secondly, the MBS resin obtained by the existing method has a wide particle size distribution, which affects its application performance. Finally, the existing method has low production efficiency and cannot meet the needs of large-scale industrial production. Therefore, how to develop a new MBS resin preparation process that can simplify the process steps, control the particle size and particle size distribution, and improve production efficiency is a problem that needs to be solved urgently in this field. Summary of the invention

[0006] In view of the problems existing in the above-mentioned prior art, the present invention proposes a method for preparing a polybutadiene latex emulsion, wherein a reactive unsaturated acid monomer is added in the middle and late stages of polymerization for polymerization, and the carboxyl groups distributed on the surface of the particles can adsorb the surrounding small-sized particles through the action of charges, thereby increasing the particle size of the emulsion.

[0007] Another object of the present invention is to provide the application of the polybutadiene latex emulsion obtained by the preparation method.

[0008] Another object of the present invention is to provide a method for preparing MBS powder.

[0009] In order to achieve the above-mentioned purpose of the invention, the present invention adopts the following technical solutions:

[0010] A preparation method of a polybutadiene latex emulsion comprises the following steps:

[0011] 1) adding 1,3-butadiene, an oxidant, a reducing agent, a accelerator, an emulsifier, and deionized water into a reaction kettle, and raising the temperature of the reaction kettle to a first temperature for reaction;

[0012] 2) raising the temperature to a second temperature, adding the unsaturated acid monomer solution, and continuing the reaction;

[0013] 3) After the temperature is lowered to the third temperature, a neutralizing agent is added to the reaction kettle, and the mixture is cooled and discharged after continued stirring to obtain a polybutadiene latex emulsion.

[0014] In some specific embodiments, the unsaturated acid monomer in step 2) includes at least component a and optional component b, wherein:

[0015] Component a is one or more unsaturated olefinic acids with carbon atoms of C3 to C10; preferably one or a combination of acrylic acid, butenoic acid, pentenoic acid, and hexenoic acid;

[0016] Component b is one or more unsaturated carboxylic acid alkyl ester monomers; preferably one or a combination of methyl methacrylate, butyl acrylate, ethyl acrylate, methyl acrylate, and isooctyl acrylate.

[0017] In some preferred embodiments, based on the total weight of the unsaturated acid monomer, component a accounts for 40-100 wt % and component b accounts for 0-60 wt %.

[0018] In some specific embodiments, the oxidant in step 1) includes one or more of persulfate, azo initiator, hydrogen peroxide, cumene hydroperoxide, dicumyl peroxide, tert-butyl hydroperoxide or benzoyl peroxide.

[0019] In some specific embodiments, the reducing agent includes one or more of thiol, ferrous salt and bisulfite, dextrose, sodium ascorbate, fructose or bleaching powder, preferably ferrous sulfate and bleaching powder.

[0020] In some specific embodiments, the accelerator includes one or more of ethylenediamine diacetate or pyrophosphate.

[0021] In some specific embodiments, the emulsifier includes one or more of sodium oleate, potassium oleate, ammonium oleate, sodium fatty acid, sodium oleyl sarcosine, ammonium lauryl sulfate, sodium dodecylbenzene sulfonate, sodium lauryl methylamide acetate, sodium alkylphenol polyoxyethylene ether sulfonate, potassium disproportionate rosin acid, sodium disproportionate rosin acid, potassium rosin acid, sodium rosin acid or sodium castor oil sulfate.

[0022] In some specific embodiments, the neutralizing agent in step 3) includes one or more of sodium hydroxide, potassium hydroxide, sodium bicarbonate, sodium acetate, sodium pyrophosphate, sodium carbonate, and ammonia water, preferably one or more of sodium hydroxide, potassium hydroxide, sodium bicarbonate, sodium acetate, and sodium pyrophosphate.

[0023] In some specific embodiments, based on the solid mass in the polybutadiene latex emulsion, calculated according to the total mass of 100%, the amount of 1,3-butadiene is 84-98.25wt%, preferably 88-95wt%; the amount of the unsaturated acid monomer is 0.5-5wt%, preferably 1-3wt%; the amount of the emulsifier is 0.5-5wt%, preferably 1-4wt%; the amount of the oxidant is 0.1-0.5wt%, preferably 0.2-0.4wt%; the amount of the reducing agent is 0.1-0.3wt%, preferably 0.15-0.25wt%; the amount of the accelerator is 0.05-0.2wt%, preferably 0.1-0.15wt%; the amount of the neutralizer is 0.5-5wt%, preferably 0.8-2wt%.

[0024] In some specific embodiments, in step 1), the amount of deionized water added is 1.0 to 3.0 times the total mass of solids in the polybutadiene latex emulsion.

[0025] In some specific embodiments, in step 1), the first temperature is 40-70° C., and the reaction time at the first temperature is 3-5 h;

[0026] In some specific embodiments, in step 2), the second temperature is 70-80° C., and the reaction time after adding the pre-emulsion containing the unsaturated acid monomer is 1-3 hours;

[0027] In some specific embodiments, the third temperature in step 3) is 30-40°C;

[0028] The first temperature is T1, the second temperature is T2, and the third temperature is T3, satisfying the following relationship: T3<T1<T2.

[0029] On the other hand, the polybutadiene latex emulsion prepared by the aforementioned preparation method is used as an MBS plasticizer.

[0030] In another aspect, a method for preparing MBS powder includes the steps of preparing the aforementioned polybutadiene latex emulsion; and grafting, flocculating, and washing the polybutadiene latex emulsion.

[0031] Compared with the existing technology, the beneficial effects of the technical solution of the present invention are as follows:

[0032] 1) Simplified process steps: The preparation process of the present invention adds unsaturated acid monomers in the middle and late stages of polymerization to carry out polymerization reaction, and adsorbs surrounding small-sized particles through charge action, thereby increasing the particle size of the emulsion. This method not only simplifies the process steps and reduces the difficulty of operation, but also reduces production costs and improves production efficiency.

[0033] 2) Precise control of particle size and particle size distribution: The preparation process of the present invention can directly synthesize large-particle polybutadiene latex, and the particle size and particle size distribution of the polybutadiene latex can be precisely controlled by adjusting the polymerization reaction conditions, such as reaction temperature, reaction time, monomer concentration, etc. The MBS resin obtained by this method has a narrow particle size distribution and good particle size control, which is conducive to improving its application performance.

[0034] 3) Improve production efficiency: The preparation process of the present invention does not need to increase the small-size particles to the desired particle size through an agglomerating agent, and can directly synthesize large-size polybutadiene latex, thereby shortening the polymerization reaction time and improving production efficiency. This highly efficient preparation process is very suitable for large-scale industrial production and can meet the market demand for MBS resin.

[0035] 4) Improving product stability: The preparation process of the present invention adds reactive acidic monomers during the polymerization stage, which can make the acidic groups on the surface of the emulsion more evenly distributed. Compared with adding non-reactive acidic substances and adding agglomerating agents after polymerization, it is more conducive to improving stability and reducing emulsion demulsification. DETAILED DESCRIPTION

[0036] The present invention is further described below by means of specific examples. The examples described in the present invention are only used to illustrate the present invention and do not limit the scope of the present invention.

[0037] The preparation method of the polybutadiene latex emulsion of the present invention abandons the method of adding agglomerating agent or prolonging polymerization time in the prior art, and adds unsaturated acid monomers to the polymerization system in the middle and late stages of polymerization, so that the monomers continue to undergo polymerization reaction with the polybutadiene latex, and utilizes the charge effect of carboxyl groups to adsorb surrounding small-sized particles. Since the unsaturated acid monomers are added during the polymerization process, carboxyl groups are distributed on the surface of the generated polybutadiene latex particles, and these carboxyl groups can adsorb surrounding small-sized particles through charge effect, thereby increasing the particle size of the emulsion.

[0038] At the same time, the method of the present invention can also effectively control the polymerization reaction time by adjusting reaction conditions, such as temperature, reactant concentration, etc., thereby improving production efficiency and meeting the needs of large-scale industrial production.

[0039] In general, compared with the prior art, the preparation process of the present invention not only simplifies the process steps and improves the production efficiency, but also accurately controls the particle size and particle size distribution, which is beneficial to improving the application performance of MBS resin.

[0040] Specifically, a process for preparing polybutadiene latex for MBS comprises the following steps:

[0041] Put butadiene, oxidant, reducing agent, promoter, emulsifier and deionized water into a polymerization reactor together, raise the temperature of the reactor to a first temperature and react for a period of time, then raise the temperature to a second temperature, add a pre-emulsion prepared by unsaturated acid monomer and water through a constant pressure pump, continue to react for a period of time, lower the temperature to a third temperature, add the prepared neutralizer to the reactor, preferably add the neutralizer within 0.1-1h, continue stirring for 0.5h, then cool and discharge, and obtain a polybutadiene emulsion.

[0042] Furthermore, the polybutadiene emulsion is grafted, flocculated and washed to obtain MBS powder.

[0043] In the present invention, the first temperature is 40-70°C, for example, 42°C, 45°C, 50°C, 53°C, 55°C, 58°C, 60°C, 62°C, 65°C, 67°C, 70°C, etc., and the reaction time at the first temperature is 3-5h, for example, 3.5h, 4h, 4.5h, etc.; the second temperature is 70-80°C, for example, 71°C, 72°C, 73°C, 74°C, 75°C, 76°C, 77°C, 78°C, 79°C, 80 ℃, etc., the time for continuing the reaction after adding the pre-emulsion containing the unsaturated acid monomer is 1-3h, for example, 1.5h, 2h, 2.5h, etc.; the third temperature in step 3) is 30-40℃, for example, 31℃, 32℃, 33℃, 34℃, 35℃, 36℃, 37℃, 38℃, 39℃, 40℃, etc.; wherein the first temperature is T1, the second temperature is T2, and the third temperature is T3, satisfying the following relationship: T3<T1<T2.

[0044] In the present invention, the unsaturated acid monomers at least include component a and optional component b, that is, the unsaturated acid monomers are component a or a mixture of component a and component b. Wherein: component a is one or more unsaturated olefinic acids with carbon atoms of C3 to C10; preferably, one or a combination of acrylic acid, butenoic acid, pentenoic acid, and hexenoic acid; component b is one or more unsaturated carboxylic acid alkyl ester monomers; preferably, one or a combination of methyl methacrylate, butyl acrylate, ethyl acrylate, methyl acrylate, and isooctyl acrylate; preferably, based on the total mass of the unsaturated acid monomers, component a accounts for 40-100wt%, such as 45wt%, 55wt%, 65wt%, 75wt%, 85wt%, 95wt%, etc., and component b accounts for 0-60wt%, such as 55wt%, 45wt%, 35wt%, 25wt%, 15wt%, 5wt%, etc.

[0045] In the present invention, the oxidant includes one or more of persulfate, azo initiator, hydrogen peroxide, cumene hydroperoxide, dicumyl peroxide, tert-butyl hydroperoxide or benzoyl peroxide; the reducing agent includes one or more of mercaptan, ferrous salt and bisulfite, dextrose, sodium ascorbate, fructose or bleaching powder, preferably ferrous sulfate and bleaching powder; the accelerator includes one or more of ethylenediamine diacetate or pyrophosphate; the emulsifier includes sodium oleate, potassium oleate, ammonium oleate , sodium fatty acid, sodium oleyl sarcosine, ammonium dodecyl sulfate, sodium dodecylbenzene sulfonate, sodium lauryl methylamine acetate, sodium alkylphenol polyoxyethylene ether sulfonate, potassium disproportionate rosin acid, sodium disproportionate rosin acid, potassium rosin acid, sodium rosin acid or castor oil sodium sulfate; the neutralizing agent includes one or more of sodium hydroxide, potassium hydroxide, sodium bicarbonate, sodium acetate, sodium pyrophosphate, sodium carbonate, and ammonia water, preferably one or more of sodium hydroxide, potassium hydroxide, sodium bicarbonate, sodium acetate, and sodium pyrophosphate.

[0046] In the present invention, based on the solid mass in the polybutadiene latex, according to the total mass of 100%, the amount of 1,3-butadiene is 84-98.25wt%, such as 85wt%, 88wt%, 91wt%, 94wt%, 97wt%, 98wt%, etc., preferably 88-95wt%; the amount of the unsaturated acid monomer is 0.5-5wt%, such as 1wt%, 1.5wt%, 2wt%, 2 .5wt%, 3wt%, 3.5wt%, 4wt%, 4.5wt%, etc., preferably 1-3wt%; the amount of the emulsifier is 0.5-5wt%, for example, 1wt%, 1.5wt%, 2wt%, 2.5wt%, 3wt%, 3.5wt%, 4wt%, 4.5wt%, etc., preferably 1-4wt%; the amount of the oxidant is 0.1-0.5wt%, for example, 0.1wt%, 0.2wt%, t%, 0.3wt%, 0.4wt%, 0.5wt%, etc., preferably 0.2-0.4wt%; the amount of the reducing agent is 0.1-0.3wt%, such as 0.1wt%, 0.15wt%, 0.2wt%, 0.25wt%, 0.3wt%, etc., preferably 0.15-0.25wt%; the amount of the accelerator is 0.05-0.2wt%, such as 0.05wt%, 0.06wt% , 0.08wt%, 0.1wt%, 0.12wt%, 0.15wt%, 0.18wt%, etc., preferably 0.1-0.15wt%; the amount of the neutralizer is 0.5-5wt%, such as 0.6wt%, 0.8wt%, 1.0wt%, 1.5wt%, 2wt%, 2.5wt%, 3wt%, 3.5wt%, 4wt%, 4.5wt%, etc., preferably 0.8-2wt%. Wherein, the amount of deionized water added is 1.0-3.0 times of the total solid mass in the polybutadiene latex emulsion, such as 1.5, 2, 2.5 times, etc. In the present invention, the solid mass or total solid mass in the polybutadiene latex emulsion is well known to those skilled in the art at the batching stage before the polymerization reaction and can usually be regarded as the theoretical solid mass.

[0047] Some specific steps in the experimental methods used in the following examples are conventional operations unless otherwise specified, such as the steps of obtaining MBS powder by polybutadiene emulsion grafting, flocculation, and washing and the performance testing method, which can be specifically referred to patent CN119409897A.

[0048] Unless otherwise specified, the materials and reagents used in the following examples can be obtained from commercial sources.

[0049] The main raw material information is as follows:

[0050] Table 1 Raw material information

[0051]

[0052]

[0053] Example 1

[0054] 320g butadiene, 0.9g cumene hydroperoxide, 0.22g sodium formaldehyde sulfoxylate, 0.3g ferrous sulfate, 0.3g disodium ethylenediaminetetraacetic acid, 7g sodium oleate, and 644g deionized water were put into a polymerization reactor, and the reactor temperature was raised to 50°C and reacted for 4h. Then the temperature was raised to 70°C, and 3g methyl methacrylate and 3g acrylic acid mixed monomer solution were added by a constant pressure pump for 1h, and the reaction was continued for 2h. The temperature was lowered to 40°C, and the prepared 6g sodium hydroxide and 60g deionized water mixed solution were added to the reactor within 0.5h, and the mixture was cooled and discharged after stirring for 0.5h. Finally, the unreacted monomers were removed by vacuum distillation to obtain a polybutadiene emulsion.

[0055] Example 2

[0056] 320g butadiene, 0.9g cumene hydroperoxide, 0.22g sodium formaldehyde sulfoxylate, 0.3g ferrous sulfate, 0.3g disodium ethylenediaminetetraacetic acid, 7g sodium oleate, and 644g deionized water were put into a polymerization reactor, and the reactor temperature was raised to 50°C and reacted for 4h. Then the temperature was raised to 70°C, and 5g methyl methacrylate and 5g acrylic acid mixed monomer solution were added by a constant pressure pump for 1h, and the reaction was continued for 3h. The temperature was lowered to 40°C, and the prepared 10g sodium hydroxide and 60g deionized water mixed solution were added to the reactor within 0.5h, and the mixture was cooled and discharged after stirring for 0.5h. Finally, the unreacted monomers were removed by vacuum distillation to obtain a polybutadiene emulsion.

[0057] Example 3

[0058] 320g butadiene, 0.9g cumene hydroperoxide, 0.22g sodium formaldehyde sulfoxylate, 0.3g ferrous sulfate, 0.3g disodium ethylenediaminetetraacetate, 7g sodium oleate, and 644g deionized water were put into a polymerization reactor, and the reactor temperature was raised to 60°C and reacted for 3.5h. Then the temperature was raised to 80°C, and 7.5g methyl methacrylate and 7.5g acrylic acid mixed monomer solution were added by a constant pressure pump for 1h, and the reaction was continued for 1h. The temperature was lowered to 40°C, and the prepared 14g sodium hydroxide and 60g deionized water mixed solution were added to the reactor within 1h, and the mixture was stirred for 0.5h, then cooled and discharged, and finally the unreacted monomers were removed by vacuum distillation to obtain a polybutadiene emulsion.

[0059] Example 4

[0060] 320g butadiene, 0.9g tert-butyl hydroperoxide, 0.22g sodium formaldehyde sulfoxylate, 0.25g ferrous sulfate, 0.25g disodium ethylenediaminetetraacetate, 8g potassium oleate, and 644g deionized water were put into a polymerization reactor, and the reactor temperature was raised to 50°C and reacted for 4h. Then the temperature was raised to 70°C, and 3g butyl acrylate and 4g butenoic acid monomer solution were added by a constant pressure pump for 1h, and the reaction was continued for 3h. The temperature was lowered to 30°C, and the prepared 7g sodium hydroxide and 60g deionized water mixed solution were added to the reactor within 1h, and the mixture was stirred for 0.5h, then cooled and discharged, and finally the unreacted monomers were removed by vacuum distillation to obtain a polybutadiene emulsion.

[0061] Example 5

[0062] 320g butadiene, 1.1g cumene hydroperoxide, 0.25g sodium formaldehyde sulfoxylate, 0.3g ferrous sulfate, 0.3g disodium ethylenediaminetetraacetate, 7g sodium oleate, and 644g deionized water were put into a polymerization reactor, and the reactor temperature was raised to 40°C and reacted for 5h. Then the temperature was raised to 75°C, and 2g methyl methacrylate and 4g acrylic acid mixed monomer solution were added by constant pressure pump for 1h, and the reaction was continued for 2.5h. The temperature was lowered to 40°C, and the prepared 6g sodium hydroxide and 60g deionized water mixed solution were added to the reactor within 0.5h, and the mixture was cooled and discharged after stirring for 0.5h. Finally, the unreacted monomers were removed by vacuum distillation to obtain polybutadiene emulsion.

[0063] Example 6

[0064] 320g butadiene, 1.1g cumene hydroperoxide, 0.22g sodium formaldehyde sulfoxylate, 0.3g ferrous sulfate, 0.3g disodium ethylenediaminetetraacetic acid, 7g sodium oleate, and 644g deionized water were put into a polymerization reactor, and the reactor temperature was raised to 70°C and reacted for 3h. Then the temperature was raised to 70°C, and a mixed monomer solution of 2g methyl acrylate and 4g hexenoic acid was added by a constant pressure pump for 1h, and the reaction was continued for 3h. The temperature was lowered to 40°C, and the prepared mixed solution of 6g sodium hydroxide and 60g deionized water was added to the reactor within 1h, and the mixture was stirred for 0.5h, then cooled and discharged, and finally the unreacted monomers were removed by vacuum distillation to obtain a polybutadiene emulsion.

[0065] Example 7

[0066] 320g butadiene, 0.9g cumene hydroperoxide, 0.22g sodium formaldehyde sulfoxylate, 0.3g ferrous sulfate, 0.3g disodium ethylenediaminetetraacetic acid, 7g sodium oleate, and 644g deionized water were put into a polymerization reactor, and the reactor temperature was raised to 50°C and reacted for 4h. Then the temperature was raised to 70°C, and a mixed monomer solution of 2.5g methyl methacrylate and 3.5g acrylic acid was added through a constant pressure pump for 1h, and the reaction was continued for 2h. The temperature was lowered to 40°C, and the prepared 6g sodium hydroxide and 60g deionized water mixed solution were added to the reactor within 0.5h, and the mixture was cooled and discharged after continued stirring for 0.5h. Finally, the unreacted monomers were removed by vacuum distillation to obtain a polybutadiene emulsion.

[0067] Example 8

[0068] 320g butadiene, 0.9g cumene hydroperoxide, 0.22g sodium formaldehyde sulfoxylate, 0.3g ferrous sulfate, 0.3g disodium ethylenediaminetetraacetic acid, 7g sodium oleate, and 644g deionized water were put into a polymerization reactor, and the reactor temperature was raised to 50°C and reacted for 4h. Then the temperature was raised to 70°C, and a mixed monomer solution of 0.2g methyl methacrylate and 5.8g acrylic acid was added through a constant pressure pump for 1h, and the reaction was continued for 2h. The temperature was lowered to 40°C, and the prepared 6g sodium hydroxide and 60g deionized water mixed solution were added to the reactor within 0.5h, and the mixture was cooled and discharged after stirring for 0.5h. Finally, the unreacted monomers were removed by vacuum distillation to obtain a polybutadiene emulsion.

[0069] Example 9

[0070] 320g butadiene, 0.4g cumene hydroperoxide, 0.2g sodium formaldehyde sulfoxylate, 0.21g ferrous sulfate, 0.21g disodium ethylenediaminetetraacetate, 2g sodium oleate, and 840g deionized water were put into a polymerization reactor, and the reactor temperature was raised to 50°C and reacted for 4h. Then the temperature was raised to 70°C, and a mixed monomer solution of 1g methyl methacrylate and 1g acrylic acid was added by a constant pressure pump for 1h, and the reaction was continued for 2h. The temperature was lowered to 40°C, and the prepared mixed solution of 2g sodium hydroxide and 60g deionized water was added to the reactor within 0.5h, and the mixture was cooled and discharged after continued stirring for 0.5h. Finally, the unreacted monomers were removed by vacuum distillation to obtain a polybutadiene emulsion.

[0071] Example 10

[0072] 240g butadiene, 1.3g cumene hydroperoxide, 0.25g sodium formaldehyde sulfoxylate, 0.5g ferrous sulfate, 0.5g disodium ethylenediaminetetraacetic acid, 13g sodium oleate, and 240g deionized water were put into a polymerization reactor, and the reactor temperature was raised to 50°C and reacted for 4h. Then the temperature was raised to 70°C, and a mixed monomer solution of 6.5g methyl methacrylate and 6.5g acrylic acid was added through a constant pressure pump for 1h, and the reaction was continued for 2h. The temperature was lowered to 40°C, and the prepared mixed solution of 13g sodium hydroxide and 60g deionized water was added to the reactor within 0.5h, and the mixture was cooled and discharged after continued stirring for 0.5h. Finally, the unreacted monomers were removed by vacuum distillation to obtain a polybutadiene emulsion.

[0073] Embodiment 11

[0074] 240g butadiene, 1.3g cumene hydroperoxide, 0.25g sodium formaldehyde sulfoxylate, 0.5g ferrous sulfate, 0.5g disodium ethylenediaminetetraacetic acid, 13g sodium oleate, and 240g deionized water were put into a polymerization reactor, and the reactor temperature was raised to 50°C and reacted for 4h. Then the temperature was raised to 70°C, and 13g acrylic acid monomer solution was added by a constant pressure pump for 1h, and the reaction was continued for 2h. The temperature was lowered to 40°C, and the prepared 13g potassium hydroxide and 60g deionized water mixed solution were added to the reactor within 0.5h, and the mixture was stirred for 0.5h, then cooled and discharged, and finally the unreacted monomers were removed by vacuum distillation to obtain a polybutadiene emulsion.

[0075] Example 12

[0076] 240g butadiene, 1.3g cumene hydroperoxide, 0.25g sodium formaldehyde sulfoxylate, 0.5g ferrous sulfate, 0.5g disodium ethylenediaminetetraacetic acid, 13g sodium oleate, and 240g deionized water were put into a polymerization reactor, and the reactor temperature was raised to 50°C and reacted for 4h. Then the temperature was raised to 70°C, and a mixed monomer solution of 10g crotonic acid was added by a constant pressure pump for 1h, and the reaction was continued for 2h. The temperature was lowered to 40°C, and the prepared mixed solution of 13g sodium bicarbonate and 60g deionized water was added to the reactor within 0.5h, and the mixture was cooled and discharged after continued stirring for 0.5h. Finally, the unreacted monomers were removed by vacuum distillation to obtain a polybutadiene emulsion.

[0077] Comparative Example 1

[0078] The polybutadiene latex was prepared by referring to the method in Example 1 of the patent publication CN104327281A.

[0079] Comparative Example 2

[0080] Compared with Example 1, the only difference is that the mixed monomer solution of methyl methacrylate and acrylic acid is not added, and other conditions are exactly the same.

[0081] Particle size test:

[0082] The polymer latex prepared in each embodiment and comparative example was grafted, flocculated, washed and dried according to the method of Example 1 of patent CN119409897A to obtain MBS powder as an impact modifier, which was added to PC instead of the toughening agent in CN119409897A to prepare a PC composite material, and the latex particle size was tested according to standard WHPU / T011-682-2015, and the cantilever beam notched impact strength was tested according to ASTM D256. The results are shown in Table 2:

[0083] Table 2 Performance test results

[0084] Aggregation time Average particle size nm Particle size distribution nm Impact strength J / m Example 1 8h 323 150-500 614 Example 2 9h 361 212-523 621 Example 3 7h 450 210-540 634 Example 4 9.5h 411 187-563 620 Example 5 9.5h 356 145-498 654 Example 6 8.5h 333 154-523 645 Example 7 8h 307 180-498 608 Example 8 8h 403 177-505 643 Example 9 8h 345 155-467 622 Example 10 8h 423 231-587 656 Embodiment 11 8h 410 234-567 645 Example 12 8h 398 200-575 634 Comparative Example 1 >10h 310 214-1385 390 Comparative Example 2 8h 123 50-231 376

[0085] It can be seen from the test results of the latex prepared in the above examples and comparative examples that the polybutadiene latex prepared by the present invention not only simplifies the process steps, but also accurately controls the particle size and particle size distribution, which is beneficial to improving the impact resistance of the MBS resin.

[0086] The above is only a preferred embodiment of the present invention. It should be pointed out that ordinary technicians in this field can make several improvements and supplements without departing from the method of the present invention. These improvements and supplements should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing a polybutadiene latex emulsion, characterized in that: The following steps are involved: 1) adding 1,3-butadiene, an oxidant, a reducing agent, a accelerator, an emulsifier, and deionized water into a reaction kettle, and raising the temperature of the reaction kettle to a first temperature for reaction; 2) raising the temperature to a second temperature, adding the unsaturated acid monomer solution, and continuing the reaction; 3) After the temperature is lowered to the third temperature, a neutralizing agent is added to the reaction kettle, and the mixture is cooled and discharged after continued stirring to obtain a polybutadiene latex emulsion.

2. The preparation method according to claim 1, characterized in that: The unsaturated acid monomer in step 2) comprises at least component a and optional component b, wherein: Component a is one or more unsaturated olefinic acids with carbon atoms of C3 to C10; preferably one or a combination of acrylic acid, butenoic acid, pentenoic acid and hexenoic acid; and / or Component b is one or more unsaturated carboxylic acid alkyl ester monomers; preferably one or a combination of methyl methacrylate, butyl acrylate, ethyl acrylate, methyl acrylate, and isooctyl acrylate.

3. The preparation method according to claim 2, characterized in that: Based on the total weight of the unsaturated acid monomer, component a accounts for 40-100 wt % and component b accounts for 0-60 wt %.

4. The preparation method according to claim 1, characterized in that: The oxidant in step 1) comprises one or more of persulfate, azo initiator, hydrogen peroxide, cumene hydroperoxide, dicumyl peroxide, tert-butyl hydroperoxide or benzoyl peroxide; and / or The reducing agent includes one or more of mercaptans, ferrous salts and bisulfites, dextrose, sodium ascorbate, fructose or bleaching powder, preferably ferrous sulfate or bleaching powder; and / or The accelerator comprises one or more of ethylenediamine diacetate or pyrophosphate; and / or The emulsifier includes one or more of sodium oleate, potassium oleate, ammonium oleate, sodium fatty acid, sodium oleyl sarcosine, ammonium lauryl sulfate, sodium dodecylbenzene sulfonate, sodium lauryl methylamine acetate, sodium alkylphenol polyoxyethylene ether sulfonate, potassium disproportionate rosin acid, sodium disproportionate rosin acid, potassium rosin acid, sodium rosin acid or sodium castor oil sulfate.

5. The preparation method according to claim 1, characterized in that: The neutralizing agent in step 3) includes one or more of sodium hydroxide, potassium hydroxide, sodium bicarbonate, sodium acetate, sodium pyrophosphate, sodium carbonate, and ammonia water, preferably one or more of sodium hydroxide, potassium hydroxide, sodium bicarbonate, sodium acetate, and sodium pyrophosphate.

6. The preparation method according to any one of claims 1 to 5, characterized in that: Based on the solid mass in the polybutadiene latex emulsion, according to the total mass of 100%, the amount of 1,3-butadiene is 84-98.25wt%, preferably 88-95wt%; the amount of the unsaturated acid monomer is 0.5-5wt%, preferably 1-3wt%; the amount of the emulsifier is 0.5-5wt%, preferably 1-4wt%; the amount of the oxidant is 0.1-0.5wt%, preferably 0.2-0.4wt%; the amount of the reducing agent is 0.1-0.3wt%, preferably 0.15-0.25wt%; the amount of the accelerator is 0.05-0.2wt%, preferably 0.1-0.15wt%; the amount of the neutralizer is 0.5-5wt%, preferably 0.8-2wt%.

7. The preparation method according to claim 6, characterized in that: In step 1), the amount of deionized water added is 1.0 to 3.0 times the total mass of solids in the polybutadiene latex emulsion.

8. The preparation method according to claim 6, characterized in that: In step 1), the first temperature is 40-70° C., and the reaction time at the first temperature is 3-5 h; and / or In step 2), the second temperature is 70-80° C., and the reaction time after adding the pre-emulsion containing the unsaturated acid monomer is 1-3 hours; and / or The third temperature in step 3) is 30-40°C; The first temperature is T1, the second temperature is T2, and the third temperature is T3, satisfying the following relationship: T3<T1<T2.

9. Use of the polybutadiene latex emulsion prepared by the preparation method according to any one of claims 1 to 8 as an MBS plasticizer.

10. A method for preparing MBS powder, characterized in that: The method comprises the steps of preparing the polybutadiene latex emulsion according to any one of claims 1 to 8; and grafting, flocculating and washing the polybutadiene latex emulsion.

Images