A polybutadiene latex and its preparation method and an ABS high-rubber powder and its preparation method and application

Abstract

The invention discloses a polybutadiene latex, wherein the dry base rubber of the polybutadiene latex contains 7-10 g / L of vinyl structure, 18-30 g / L of Trans-1,4 butadiene structure, and 10-24 g / L of Cis-1,4 butadiene structure. The polybutadiene latex of the invention has a low horizontal combustion speed. The invention also discloses a preparation method of the polybutadiene latex and an application thereof in ABS high-rubber powder, wherein the ABS resin obtained by blending the ABS high-rubber powder has a low horizontal combustion speed.

Description

Technical Field

[0001] The invention relates to the technical field of polymer materials, in particular to a polybutadiene latex and a preparation method thereof, and an ABS high-rubber powder and a preparation method and application thereof. Background Art

[0002] ABS resin has the advantages of excellent heat resistance, impact resistance, rigidity, corrosion resistance and dimensional stability, and is widely used in many fields such as household appliances, electronic and electrical products, industrial parts and accessories, and the automotive industry. ABS resin is one of the five major engineering plastics, with good mechanical properties and processing properties, and is widely used in automobile manufacturing, household appliance production and other fields. ABS resin is a thermoplastic resin with an island structure formed by dispersing polybutadiene rubber phase in SAN resin formed by copolymerization of styrene and acrylonitrile. At present, the methods for preparing ABS resin widely use two methods: continuous bulk method and emulsion grafting-bulk SAN blending method.

[0003] The emulsion grafting-bulk SAN blending method has become the mainstream method for ABS resin production on the market due to its strong versatility, flexible formula switching, wide range of products that can be produced, and large output of a single set of equipment. The emulsion grafting-bulk SAN blending method is to polymerize butadiene through an emulsion method to obtain polybutadiene latex (PBL), then graft polymerize styrene and acrylonitrile on the polybutadiene latex particles, and then obtain ABS grafted powder after condensation and drying, and then mix it with SAN resin and extrude and granulate it to obtain ABS resin.

[0004] With the development of large-scale home appliance industry and thin-walled OA industry, higher requirements are put forward for the stability of material performance. ABS resin is generally used for shells, but the horizontal burning speed of the materials currently on the market is difficult to reach HB75, which cannot meet the requirements of the industry well. Summary of the invention

[0005] The object of the present invention is to provide a polybutadiene latex with a low horizontal burning speed and a preparation method thereof, and to provide ABS high-rubber powder obtained from the polybutadiene latex, which also has the advantage of a low horizontal burning speed.

[0006] The present invention is achieved through the following technical solutions:

[0007] A polybutadiene latex, wherein the dry base rubber of the polybutadiene latex contains 7-10 g / L of vinyl structure, 18-30 g / L of Trans-1,4 butadiene structure and 10-24 g / L of Cis-1,4 butadiene structure.

[0008] The above parameters are characterized and measured by SH / T 1727-2004. Preferably, the dry base rubber in the polybutadiene latex contains 8-9 g / L of vinyl structure, 22-26 g / L of Trans-1,4 butadiene structure, and 10-16 g / L of Cis-1,4 butadiene structure.

[0009] The preparation method of the polybutadiene latex of the invention comprises the following steps: adding 85-95 parts of butadiene in an initial amount, 0.1-1 parts of initiator, 0.5-2 parts of electrolyte, 1-5 parts of emulsifier, 0.1-1 parts of chain transfer agent and 90-200 parts of water into a reactor by weight and mixing them uniformly, heating to 55-85°C for polymerization reaction; when the butadiene conversion rate is 50%≤≤70%, starting to add the remaining butadiene monomer to 100 parts, controlling the addition to be completed within 2-4 hours, during which the temperature is controlled at 55-85°C, and when the total conversion rate of butadiene monomers is ≥95%, the polybutadiene latex is obtained.

[0010] Preferably, the process parameters of the preparation method are as follows: by weight, 88-93 parts of butadiene are initially added, 0.2-0.8 parts of initiator, 0.8-1.5 parts of electrolyte, 1.5-4.5 parts of emulsifier, 0.2-0.8 parts of chain transfer agent and 90-200 parts of water are added into a reactor and mixed evenly, and the temperature is raised to 60-80° C. for polymerization reaction; when 55%≤butadiene conversion rate≤65%, the remaining butadiene monomer is added to 100 parts, and the addition is completed within 2.5-3.5 hours, during which the temperature is controlled at 65-75° C., and when the total conversion rate of butadiene monomers is ≥95%, polybutadiene latex is obtained.

[0011] Optionally, the emulsifier is selected from anionic emulsifiers; the anionic emulsifier is selected from at least one of potassium oleate, potassium disproportionated rosin acid, sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, and dioctyl sodium sulfosuccinate.

[0012] The electrolyte is selected from at least one of potassium bicarbonate, potassium carbonate, sodium bicarbonate, sodium carbonate and sodium tripolyphosphate;

[0013] The chain transfer agent is selected from at least one of n-butyl mercaptan, n-octyl mercaptan, n-dodecyl mercaptan and tert-dodecyl mercaptan;

[0014] The initiator includes (but is not limited to): hydrogen peroxide compounds, such as tert-butyl peroxide (di-tert-butyl peroxide, tert-butyl hydroperoxide, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane), peroxy ketal compounds, such as 1,1-bis-tert-butylperoxy-3,3,5-trimethylcyclohexane, 2,2-bis(4,4-di(tert-butylperoxy)cyclohexyl)propane, alkanes, etc.; peroxyester compounds, such as tert-butyl peroxypivalate, 2,5-dimethyl-2,5-di(2-ethylhexanol peroxide)hexane, etc.; peroxyketal compounds, such as 4,4-diperoxytert-butyl-pentanoic acid-n-butyl ester, etc.; peroxycarbonate compounds, such as 2-ethylhexyl tert-amyl peroxycarbonate, 2-ethylhexyl tert-butyl peroxycarbonate, etc.; or azo compounds with nitro and cyclohexane, etc.

[0015] An ABS high-rubber powder using the polybutadiene latex of the present invention comprises the following components by weight percentage:

[0016] 20-80 wt% of polybutadiene in the polybutadiene latex of the present invention;

[0017] Polybutadiene surface grafted and blended SAN 20-80wt%.

[0018] The polybutadiene latex obtained by the preparation method of the polybutadiene latex of the present invention is further grafted with styrene-acrylonitrile copolymer, condensed, dehydrated, dried, and then blended with SAN to obtain ABS high-rubber powder.

[0019] The preparation method of ABS high-rubber powder is as follows: add the above 60 parts of polybutadiene latex into a reactor, add 2-4 parts of ferrous sulfate into the reactor and stir evenly, heat the reactor to 65-70°C, add 0.1-0.5 parts of cumene hydroperoxide (initiator), 35-70 parts of acrylonitrile / styrene, 0.1-0.3 parts of tert-dodecyl mercaptan, 1-3 parts of sodium dodecyl sulfonate and 50-70 parts of deionized water, continue to react for 4-6 hours after heating, and obtain grafted latex. Take the grafted latex and add it into a coagulation reactor, start stirring and heat to 70-80°C, gradually add ethyl sulfuric acid thereto, add it completely over 1-4 hours, heat it to 88-95°C and keep the temperature for 1-5 hours, filter the obtained coagulated latex, dry it, and then blend it with SAN through a twin-screw extruder to obtain ABS high-rubber powder.

[0020] The present invention has the following beneficial effects:

[0021] Butadiene polymerization is divided into tetrapolymerization and dipolymerization. The units obtained by tetrapolymerization contain cis / trans structures, and the units obtained by dipolymerization are vinyl. The present invention mainly controls the addition speed of butadiene monomer and the timing of adding monomer (butadiene conversion rate), reaction temperature, and the addition amount of each component in the preparation process of polybutadiene latex, and controls the content of 1,2 structure and cis-1,4 structure in the main rubber to make both reach a specific content range, so that the ABS high rubber powder prepared by the polybutadiene latex of the present invention has a lower horizontal combustion speed.

[0022] The inventors have found through experiments that the 1,2 structure in the main butadiene rubber can provide tertiary carbon atoms during the combustion process, and is very active during the combustion process, reacting with oxygen to produce free radicals to promote polymer decomposition; the cis-1,4 structure is easy to produce cyclic structure molecules during the combustion process. During the horizontal combustion process of ABS resin, polybutadiene is preferentially decomposed, and the content of active tertiary carbon atoms is reduced, which is more conducive to the formation of cyclic structure molecules such as cyclohexene ethylene and polydipentene, increasing the molecular weight of organic molecules in the gas phase, making thermal radiation heat transfer dominant, thereby reducing the flame spread rate. The ABS resin prepared by the polybutadiene latex of the present invention has a very low horizontal combustion rate and is particularly suitable for thin-wall flame retardant applications. DETAILED DESCRIPTION

[0023] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several variations and improvements may be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0024] The sources of raw materials required for the preparation of ABS high-rubber powder of the present invention are as follows:

[0025] Emulsifier:

[0026] A: Potassium disproportionate rosin acid, purity 98%, Aladdin;

[0027] B: Potassium oleate, purity 98%, Aladdin;

[0028] Electrolytes:

[0029] A: Potassium carbonate, industrial grade, Ulead;

[0030] B: Potassium bicarbonate, industrial grade, Unid;

[0031] Chain transfer agent:

[0032] A: tert-Dodecyl mercaptan, purity 99.5%, Aladdin;

[0033] B: n-Dodecyl mercaptan, purity 98%, Chevron Phillips;

[0034] Initiator:

[0035] A: tert-butyl peroxide, di-tert-butyl peroxide, purity 97%, Aladdin;

[0036] B: tert-butyl peroxypivalate, initiator LQ-TBPV, Lanzhou Auxiliary Agent Factory;

[0037] Preparation method of polybutadiene latex in embodiments and comparative examples (addition of each raw material is shown in the table): butadiene, initiator, electrolyte, emulsifier, chain transfer agent, and 130 parts of water are added into a reactor by weight and mixed evenly, and polymerization reaction is carried out at a specific temperature (specific temperature is shown in the table, note the reaction temperature of stage 1); when 50%≤butadiene conversion rate≤70% (specific conversion rate is shown in the table, and the conversion rates of latex 17 / 18 are 46.2% and 74.1%, respectively), butadiene monomer is added, the time used for adding butadiene (see the table), the reaction temperature is controlled (specific temperature is shown in the table, note the reaction temperature of stage 2), and when the total conversion rate of butadiene monomers is ≥95%, polybutadiene latex is obtained.

[0038] Various test methods:

[0039] (1) Conversion rate test: The test method for residual butadiene monomer in latex is to take 0.1g sample into a 20ml headspace bottle, dilute it to 2g with DMF, and analyze the sample using a PE TurboMatrix 40 headspace injector and a Shimadzu GC 2010 gas chromatograph to test the residual butadiene monomer content, and then calculate the mass of the residual butadiene monomer in the reactor. Butadiene conversion rate calculation: Butadiene conversion rate = (total mass of butadiene added to the reactor - mass of residual butadiene monomer in the reactor) / total mass of butadiene added to the reactor.

[0040] (2) The method for determining the dry rubber structure in polybutadiene latex is carried out in accordance with the test standard SH / T 1727-2004. Take 100g of butadiene latex smear sample, dry it at 80℃ to constant weight, extract it in ethanol / toluene (ETA), and then vacuum dry it at 50-60℃; take 100mg of the extracted sample, dissolve it in 20mg of dichloromethane, and filter the glue solution; add 3-4 drops of glue solution on a horizontally placed salt sheet, and evaporate the solvent at room temperature; use BRUKER's TENSOR 27 infrared spectrometer at 2000-600cm -1 Scan internally and draw the baseline. Measure 965 (A 965 )cm -1 ,900(A 909 )cm -1 , and 728(A 728 )cm-1 The absorbance of the wave number characterizes the trans (A965), vinyl (A909) and cis (A728) contents respectively. The absorbance is normalized:

[0041] %A 965 =A 965 / (A 965 +A 909 +A 728 )×100;

[0042] %A 909 =A 909 / (A 965 +A 909 +A 728 )×100;

[0043] %A 728 =A 728 / (A 965 +A 909 +A 728 )×100;

[0044] The trans (A965), vinyl (A909) and cis (A728) contents are calculated according to the following formula, in g / L:

[0045] C cis = 1.7896 × % A 728 -0.0253 × %A 965 -0.085×%A 909 ;

[0046] C trans=0.3971×%A 965 -0.0502 × %A 728 -0.0142 × %A 909 ;

[0047] C vinyl = 0.2954 × % A 909 -0.0075 × %A 728 -0.0065 × %A 965 .

[0048] (3) Horizontal burning rate (HB burning rate) test method: According to the test standard UL94-2000, the sample thickness of ABS high rubber powder is 2.0 mm.

[0049] Table 1: Parameters (parts by weight) and test results of polybutadiene latex

[0050]

[0051]

[0052] It can be seen from Latex-1 to Latex-9 that the preferred process of polybutadiene latex can obtain a latex having a preferred structural polybutadiene composition.

[0053] Table 1 continued:

[0054]

[0055] Table 1 continued:

[0056]

[0057] It can be seen from latexes 10 to 18 that without adopting the process of the present invention, it is impossible to obtain the latex composed of the polybutadiene with the specific structure applied for in the present invention.

[0058] Preparation method of ABS high-rubber powder: 60 parts of polybutadiene latex obtained in the above experimental example are added to a reactor according to the formula in Table 2, and 3 parts of ferrous sulfate are added to the reactor and stirred evenly, the reactor is heated to 67°C, and 0.2 parts of cumene hydroperoxide, acrylonitrile / styrene (the final weight content of SAN is shown in the table), 0.2 parts of tert-dodecyl mercaptan, 1 part of sodium dodecyl sulfonate and 50 parts of deionized water are added, and the addition is continued for 2 hours. After the heating is completed, the reaction is continued for 5 hours to obtain a grafted latex. 1000 parts of the grafted latex are added to a coagulation reactor, stirring is started and heated to 75°C, 450 parts of 5% sulfuric acid are gradually added thereto, and the addition is completed within 2 hours, and the temperature is raised to 91°C and maintained for 3 hours. The obtained coagulated latex is filtered with a 325-mesh filter and dried at 60°C for 6 hours with a fluidized bed dryer, and then SAN is blended through a twin-screw extruder (the final weight content of SAN is shown in the table) to obtain an ABS high-rubber powder with a moisture content of <1%.

[0059] Among them, the test results of the source of polybutadiene latex and the content of each unit (weight percentage) are as follows

[0060] Table 2:

[0061]

[0062] Table 2 continued:

[0063]

[0064] Table 2 continued:

[0065]

[0066]

[0067] From the above test examples, it can be seen that the ABS high-rubber powder prepared from the preferred latex containing polybutadiene with a specific structure has a slow horizontal combustion speed, while the horizontal combustion speed of the ABS high-rubber powder of ABS high-rubber powder -10 to 18 (comparative example) is too fast.

Claims

1. A polybutadiene latex, characterized in that: The dry base rubber in the polybutadiene latex contains 7-10 g / L of vinyl structure, 18-30 g / L of Trans-1,4 butadiene structure and 10-24 g / L of Cis-1,4 butadiene structure.

2. The polybutadiene latex according to claim 1, characterized in that The dry base rubber in the polybutadiene latex contains 8-9 g / L of vinyl structure, 22-26 g / L of Trans-1,4 butadiene structure and 10-16 g / L of Cis-1,4 butadiene structure.

3. The method for preparing the polybutadiene latex according to any one of claims 1 to 2, characterized in that: The method comprises the following steps: adding 85-95 parts of butadiene in an initial amount, 0.1-1.0 parts of initiator, 0.5-2 parts of electrolyte, 1-5 parts of emulsifier, 0.1-1 parts of chain transfer agent and 90-200 parts of water into a reactor by weight, mixing them evenly, heating to 55-85° C. to carry out polymerization reaction; when the butadiene conversion rate is 50%≤≤70%, starting to add the remaining butadiene monomer to 100 parts, controlling the addition to be completed within 2-4 hours, during which the temperature is controlled at 55-85° C., and when the total conversion rate of butadiene monomers is ≥95%, obtaining polybutadiene latex.

4. The method for preparing polybutadiene latex according to claim 3, characterized in that: The method comprises the following steps: adding 88-93 parts of butadiene in an initial amount, 0.2-0.8 parts of initiator, 0.8-1.5 parts of electrolyte, 1.5-4.5 parts of emulsifier, 0.2-0.8 parts of chain transfer agent and 90-200 parts of water into a reactor by weight, mixing them evenly, heating to 60-80 DEG C to carry out polymerization reaction; when the butadiene conversion rate is 55%≤≤65%, starting to add the remaining butadiene monomer to 100 parts, controlling the addition to be completed within 2.5-3.5 hours, during which the temperature is controlled at 65-75 DEG C, and when the total conversion rate of butadiene monomers is ≥95%, obtaining polybutadiene latex.

5. The method for preparing polybutadiene latex according to claim 3, characterized in that: The emulsifier is selected from anionic emulsifiers; the anionic emulsifier is selected from at least one of potassium oleate, potassium disproportionated rosin acid, sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, and dioctyl sodium sulfosuccinate; the electrolyte is selected from at least one of potassium bicarbonate, potassium carbonate, sodium bicarbonate, sodium carbonate, and sodium tripolyphosphate; the chain transfer agent is selected from at least one of n-butyl mercaptan, n-octyl mercaptan, n-dodecyl mercaptan, and tert-dodecyl mercaptan; the initiator is selected from at least one of hydrogen peroxide compounds, peroxyketal compounds, peroxyester compounds, peroxyketal compounds, peroxycarbonate compounds, and azo compounds with nitro and cyclohexane.

6. An ABS high-rubber powder, characterized in that: By weight percentage, it includes the following components: 20-80 wt % of polybutadiene in the polybutadiene latex according to any one of claims 1 to 2; Polybutadiene surface grafted and blended SAN 20-80wt%.

7. The method for preparing the ABS high-rubber powder according to claim 6, characterized in that: The method comprises the following steps: grafting styrene and acrylonitrile onto the polybutadiene latex as claimed in any one of claims 1 to 2, and then coagulating, dehydrating, drying, and blending with SAN to obtain ABS high-rubber powder.

8. The use of the ABS high-rubber powder according to claim 6, characterized in that: Used for thin-wall flame retardant parts.

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