Double-distribution ASA latex and application thereof

Abstract

The invention provides dual-distribution ASA latex and application thereof.The dual-distribution ASA latex comprises first latex and second latex, the first latex comprises a shell layer and a core layer, the core layer is poly (butyl acrylate) latex with the average particle size ranging from 50 nm to 150 nm, the shell layer is styrene-acrylonitrile copolymer, and the mass-average molecular weight of the styrene-acrylonitrile copolymer ranges from 4 w to 8 w; the second latex comprises a shell layer and a core layer, the core layer is poly (butyl acrylate) latex with the average particle size of 350-450 nm, the shell layer is a styrene-acrylonitrile copolymer, and the mass-average molecular weight of the styrene-acrylonitrile copolymer is 10-20 w. The ASA latex prepared by the method has dual-distribution particle size, and ASA resin prepared by the ASA latex prepared by the method has excellent impact strength and glossiness.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of high polymers, and particularly relates to a kind of double distribution ASA latex and its use. BACKGROUND

[0002] ASA resin is a kind of engineering plastic with excellent performance, which belongs to butyl acrylate-styrene-acrylonitrile terpolymer, has "island" structure, the matrix phase is styrene-acrylonitrile copolymer, the dispersed phase has core-shell structure, the polybutyl acrylate rubber phase is the core, which can play the toughening effect to provide impact resistance for the resin, and the styrene-acrylonitrile resin (SAN) is the shell, which enhances the compatibility of the dispersed phase and the continuous phase.

[0003] The rubber phase in the ASA resin is polybutyl acrylate, which has high glass transition temperature and is difficult to induce craze and cavitation when impacted, so the rubber toughening efficiency is low, resulting in poor impact resistance of the ASA resin. At the same time, with the vigorous promotion of new energy vehicles, the appearance of vehicles tends to be high-gloss and cool, so the gloss of the ASA resin needs to be improved. The existing method to improve the gloss of the ASA resin is to blend ASA with PMMA, but the improvement of the gloss of the ASA resin is limited, and the impact performance of the material is also reduced, which limits its application in the automotive field.

[0004] An effective method to improve the impact strength of the ASA resin is to blend different particle sizes or increase the amount of ASA powder. For example, Wu Kunpeng et al. (Effect of Rubber Particle Size and Its Synergistic Effect on ASA Toughened SAN Resin, Wu Kunpeng, Yu Jinsuo, Kong Lei, 2023) prepared high-impact ASA resin by blending 100 nm particle size ASA powder with 600 nm particle size ASA powder in a certain proportion, and the impact strength reached 600 J / m. However, in this method, the amount of powder added is large, and the particle size is too large, which reduces the gloss of the resin.

[0005] In summary, how to create an ASA resin with good gloss and excellent impact strength has become a difficult problem that needs to be solved in the industry. SUMMARY

[0006] In view of the above problems existing in the prior art, one of the purposes of the present application is to provide a kind of double distribution ASA latex, which is prepared by two different rubber particle size latexes to obtain a latex with core-shell structure, which not only helps to improve the gloss, but also the small particle size has a lower molecular weight and a thinner grafting shell layer, which makes it moderately agglomerate during processing, and the large particle size has a higher molecular weight of grafting shell layer, which makes it uniformly dispersed during processing, bringing excellent impact strength.

[0007] The second purpose of the present application is to provide the use of the ASA latex, which is used for preparing ASA resin, and the resin has high gloss and high impact strength.

[0008] To achieve the above object, the present application adopts the following technical solutions:

[0009] In a first aspect, the present application provides a double distribution ASA latex, comprising a first latex and a second latex, wherein the first latex comprises a core layer and a shell layer, wherein the core layer is a polybutyl acrylate latex with an average particle size of 50-150 nm, and the shell layer is a styrene-acrylonitrile copolymer with a mass average molecular weight of 4-8 w;

[0010] The second latex comprises a core layer and a shell layer, wherein the core layer is a polybutyl acrylate latex with an average particle size of 350-450 nm, and the shell layer is a styrene-acrylonitrile copolymer with a mass average molecular weight of 10-20 w,

[0011] Preferably, the difference between the solubility parameters SP of the shell layers of the first latex and the second latex is 0.5-0.8 (cal / cm 3 ) 1 / 2 .

[0012] Preferably, the core-shell ratio of the first latex is 9:1-5:5, and the core-shell ratio of the second latex is 7:3-3:7.

[0013] Preferably, the double distribution ASA latex is obtained by mixing the first latex and the second latex.

[0014] Preferably, in the ASA latex, the mass fraction of the first latex is 99wt%-30wt%, preferably 70wt%-50wt%, and the mass fraction of the second latex is 1wt%-70wt%, preferably 30wt%-50wt%.

[0015] Preferably, the first latex and the second latex can be prepared by using the existing known preparation method of ASA latex.

[0016] In some preferred embodiments of the present application, the first latex and the second latex can be independently prepared by the following method:

[0017] S1: Put butyl acrylate, a first emulsifier, a first crosslinking agent, an electrolyte and water into a reactor, and mix and heat under nitrogen;

[0018] S2: Add a first initiator to the reactor to prepare a seed emulsion;

[0019] S3: Add butyl acrylate, a second crosslinking agent, a second emulsifier, water and a second initiator to the reactor for further reaction to prepare a polybutyl acrylate latex;

[0020] S4: adding styrene, acrylonitrile, third emulsifier, chain transfer agent, water, third initiator, reducing agent into the polybutyl acrylate latex, and reacting at the reaction temperature to prepare the ASA emulsion.

[0021] In an embodiment of the present application, the first emulsifier and the second emulsifier are the same or different, and are independently one or more of sodium dodecyl sulfate, sodium dodecyl benzene sulfonate, potassium oleate, potassium disproportionated rosin acid, and sodium dioctyl sulfonated succinate. Preferably, the first emulsifier and the second emulsifier are the same.

[0022] In an embodiment of the present application, the first crosslinking agent and the second crosslinking agent are the same or different, and are independently one or more of divinyl benzene, allyl methacrylate, ethylene glycol acrylate, 1,3-butanediol dimethacrylate, 1,4-butanediol dimethacrylate, triallyl isocyanurate, triallyl cyanurate, diallyl maleate, dicyclopentadiene acrylate. Preferably, the first crosslinking agent and the second crosslinking agent are the same.

[0023] In an embodiment of the present application, the electrolyte is an inorganic salt, and is preferably one or more of potassium bicarbonate, potassium carbonate, sodium bicarbonate, sodium carbonate, sodium tripolyphosphate.

[0024] In some embodiments of the present application, the amounts of the components in S1 are as follows: acrylate 1-4 parts by weight, emulsifier 0.002-2 parts by weight, crosslinking agent 0-0.2 parts by weight, electrolyte 0-0.8 parts by weight, water 30-80 parts by weight.

[0025] In an embodiment of the present application, the holding temperature in S1 is 40-70°C.

[0026] In an embodiment of the present application, the first initiator in S2 is selected from one or more of inorganic peroxide and / or organic peroxide, and is preferably one or more of potassium persulfate, sodium persulfate, ammonium persulfate, dicumyl peroxide, cumene hydroperoxide.

[0027] In an embodiment of the present application, the reaction time in S2 is 0.5-1h.

[0028] In an embodiment of the present application, the amount of the first initiator added in S2 is 0.002-0.02 parts by weight.

[0029] In an embodiment of the present application, the amounts of the components in S3 are as follows: butyl acrylate 49-76 parts by weight, second emulsifier 0.15-0.75 parts by weight, second crosslinking agent 0.2-3.8 parts by weight, water 50-80 parts by weight, second initiator 0.05-2 parts by weight.

[0030] In one embodiment of the present application, the second initiator in S3 is selected from inorganic peroxide and / or organic peroxide, preferably one or more of potassium persulfate, sodium persulfate, ammonium persulfate, dicumyl peroxide, cumene hydroperoxide.

[0031] In one embodiment of the present application, the dropping time in S3 is 2-5h.

[0032] In one embodiment of the present application, the holding time in S3 is 1-2h.

[0033] In one embodiment of the present application, the reaction temperature in S3 is 40-70℃, preferably, the reaction temperature in S3 is the same as that in S1.

[0034] In one embodiment of the present application, the third emulsifier in S4 is 0.3-1 parts by weight, the chain transfer agent is 0-0.5 parts by weight, water is 50-100 parts by weight, the third initiator is 0.15-0.5 parts by weight, and the reducing agent is 0.02-0.06 parts by weight.

[0035] In one embodiment of the present application, the third emulsifier in S4 is an anionic emulsifier, preferably one or more of sodium dodecyl sulfate, sodium dodecyl benzene sulfonate, potassium oleate, potassium disulfated rosin acid, and sodium dioctyl sulfonated succinate.

[0036] In one embodiment of the present application, the chain transfer agent in S4 is selected from alkyl mercaptan compounds, preferably one or more of n-octyl mercaptan, tert-dodecyl mercaptan, n-dodecyl mercaptan.

[0037] In one embodiment of the present application, the third initiator in S4 is selected from organic peroxide, preferably one or more of tert-butyl hydroperoxide, dicumyl peroxide, cumene hydroperoxide.

[0038] In one embodiment of the present application, the reducing agent in S4 is preferably one or more of ferrous sulfate, glucose, sodium pyrophosphate, sodium thiosulfate, disodium EDTA.

[0039] In one embodiment of the present application, the adding time of each component in S4 is 2-5h.

[0040] In one embodiment of the present application, the holding time in S4 is 1-3h.

[0041] In one embodiment of the present application, the reaction temperature in S4 is 40-70℃, preferably, the reaction temperature in S4 is the same as that in S3.

[0042] The particle size of the polybutyl acrylate latex can be controlled by controlling the amount of emulsifier, initiator and butyl acrylate added. For example, when preparing a small particle size polybutyl acrylate latex, the amount of the first emulsifier added can be 0.1-2 parts by weight, and when preparing a large particle size polybutyl acrylate latex, the amount of the first emulsifier added can be 0.002-0.04 parts by weight.

[0043] The mass average molecular weight of the shell layer styrene-acrylonitrile copolymer can be controlled by means known in the art, such as by controlling the amount of initiator, chain transfer agent, reaction monomer added, reaction temperature, etc. For example, when preparing the first latex, the amount of chain transfer agent added in S4 can be 0.1-0.5 parts by weight, and when preparing the second latex, the amount of chain transfer agent added in S4 can be 0.

[0044] The solubility parameter SP of the shell layer styrene-acrylonitrile copolymer is calculated by the weighted average of the monomer molar ratio, such as SP = (poly-styrene SP * poly-styrene molar mass + poly-acrylonitrile SP * poly-acrylonitrile molar mass / styrene-acrylonitrile copolymer molar mass), which can be controlled by means known in the art, such as by controlling the amount of reaction monomer added.

[0045] Mixing the first latex and the second latex can obtain the ASA latex of the present application,

[0046] In the present application, the ASA latex prepared is coagulated, dehydrated and dried to obtain ASA rubber powder.

[0047] Preferably, the ASA latex is coagulated and demulsified by calcium chloride.

[0048] The present application also provides the use of the ASA latex, which is prepared into ASA rubber powder and then mixed with a thermoplastic resin to obtain an ASA resin.

[0049] The method for preparing the ASA resin can be known in the art and will not be repeated here.

[0050] The present application also provides the use of the ASA resin, which is applied in the fields of automobiles, household appliances, office supplies, etc., preferably in the field of automobiles.

[0051] Compared with the prior art, the technical scheme of the present application has the following beneficial effects:

[0052] The present application adopts latexes with different particle sizes to obtain a double distribution ASA latex, which has the advantages of small particle size and low molecular weight and thin grafting shell layer, and moderate agglomeration in the processing process, and the difference between the solubility parameters SP of the shell layers of the latexes with different particle sizes is 0.5-0.8 (cal / cm 3 ) 1 / 2The small particle size and the large particle size are not easily compatible, the large particle size has a higher molecular weight of the grafted shell layer, and is uniformly dispersed in the processing process, thereby bringing excellent impact strength. BRIEF DESCRIPTION OF DRAWINGS

[0053] Figure 1 TEM image of the ASA latex provided in Example 1;

[0054] Figure 2 TEM image of the ASA resin provided in Comparative Example 1. DETAILED DESCRIPTION

[0055] In order to better understand the technical solutions of the present application, the content of the present application will be further described below in combination with examples, but the content of the present application is not limited to the following examples only.

[0056] In the following examples and comparative examples of the present application, the source information of raw materials is not particularly specified, and the raw materials used in the examples or comparative examples are obtained from commercial channels.

[0057] Butyl acrylate, produced in Wanhua Chemical Industrial Park;

[0058] Sodium dodecyl sulfate, 99%, purchased from Aldrich;

[0059] Cumene hydroperoxide, 80%, purchased from Aldrich;

[0060] Tert-butyl hydroperoxide, 70%, purchased from Aldrich;

[0061] Potassium oleate, BM-400, purchased from Innochem;

[0062] Ferrous sulfate, 99%, purchased from Xilong Chemical;

[0063] Glucose, 99%, purchased from Xilong Chemical;

[0064] Sodium pyrophosphate, 99%, purchased from Aldrich;

[0065] Allyl methacrylate, 99%, purchased from Aldrich;

[0066] Acrylonitrile, 99%, purchased from Aldrich;

[0067] Styrene, 99%, purchased from Aldrich;

[0068] Potassium carbonate, 99%, purchased from Aldrich.

[0069] The following test methods were used in the examples of the present application:

[0070] Solubility parameter: SP = (polystyrene SP * polystyrene molar mass + polyacrylonitrile SP * polyacrylonitrile molar mass / styrene-acrylonitrile copolymer molar mass), wherein polystyrene SP = 9.1, the styrene molecular weight is 104.15, and acrylonitrile SP = 15.4, the acrylonitrile molecular weight is 53.06.

[0071] Latex particle size: The latex was diluted 20,000 times with deionized water, and the particle size was measured using a Malvern particle size analyzer Zetasizer Nano-ZS90.

[0072] Transmission electron microscopy: The ASA resin section was dyed with ruthenium tetroxide solution, and the structure of the polymer was observed. Transmission electron microscope (TEM) manufacturer: Thermo Fisher, model: Talos F200c.

[0073] Mechanical properties: Charpy notched impact standard ASTM D256, 23°C, using Italian CEAST 9050.

[0074] Glossiness: ASTM D523 was used to test 60. Glossiness, BYK-Gardner GmbH.

[0075] Example 1

[0076] 3 parts by mass of butyl acrylate, 1 part by mass of sodium dodecyl sulfate, 0.5 parts by mass of potassium carbonate, and 50 parts by mass of deionized water were added to the reactor, nitrogen was introduced, mixed, and incubated at 50°C. 0.015 parts by mass of potassium persulfate was added to the reactor, and the reaction was carried out for 0.6 h to prepare a seed emulsion. 60 parts by mass of butyl acrylate, 2 parts by mass of allyl methacrylate, 0.5 parts by mass of sodium dodecyl sulfate, 60 parts by mass of water, and 1 part by mass of sodium persulfate were added dropwise to the reactor, the dropwise addition time was 3 h, and the reaction was carried out at 50°C for 1.5 h to prepare a small-particle-size PBA emulsion. 20.2 parts by mass of styrene, 7.8 parts by mass of acrylonitrile, 0.5 parts by mass of sodium dodecyl sulfate, 0.2 parts by mass of tertiary dodecyl mercaptan, 70 parts by mass of water, 0.3 parts by mass of cumene hydroperoxide, and 0.04 parts by mass of ferrous sulfate / ferrous sulfate were added dropwise to the reactor, the dropwise addition time was 3 h, and the reaction was carried out for 2 h to prepare a first ASA emulsion.

[0077] Into a reactor, 3 parts by mass of butyl acrylate, 0.01 part by mass of sodium dodecyl sulfate, 0.5 part by mass of potassium carbonate and 50 parts by mass of deionized water were added, nitrogen was introduced, mixed and kept at 50°C. Into the reactor, 0.015 part by mass of potassium persulfate was added, and reacted for 0.6 h to prepare a seed emulsion. Into the reactor, 60 parts by mass of butyl acrylate, 2 parts by mass of allyl methacrylate, 0.5 part by mass of sodium dodecyl sulfate, 60 parts by mass of water and 1 part by mass of sodium persulfate were added dropwise, the dropwise addition time was 3 h, and the reaction was kept at 50°C for 1.5 h to prepare a large particle size PBA emulsion. Into the reactor, 33 parts by mass of styrene, 9 parts by mass of acrylonitrile, 0.5 part by mass of sodium dodecyl sulfate, 70 parts by mass of water, 0.3 part by mass of cumene hydroperoxide and 0.04 part by mass of ferrous sulfate / azodicarbonamide were added dropwise, the dropwise addition time was 3 h, and the reaction was kept for 2 h to prepare a second ASA emulsion.

[0078] The two kinds of latexes were mixed to obtain a double distribution ASA latex, wherein the mass ratio of the first ASA latex was 60%.

[0079] The particle sizes of the small particle size PBA latex, the large particle size PBA latex, the shell molecular weight of the first ASA emulsion and the second ASA emulsion prepared in this example are shown in Table 1.

[0080] Example 2

[0081] Into a reactor, 1 part by mass of butyl acrylate, 0.1 part by mass of sodium dodecylbenzenesulfonate, 0.2 part by mass of divinylbenzene, 0.8 part by mass of potassium bicarbonate and 30 parts by mass of deionized water were added, nitrogen was introduced, mixed and kept at 40°C. Into the reactor, 0.002 part by mass of sodium persulfate was added, and reacted for 0.5 h to prepare a seed emulsion. Into the reactor, 49 parts by mass of butyl acrylate, 0.2 part by mass of divinylbenzene, 0.15 part by mass of sodium dodecylbenzenesulfonate, 50 parts by mass of water and 0.05 part by mass of potassium persulfate were added dropwise, the dropwise addition time was 2 h, and the reaction was kept for 1 h to prepare a small particle size PBA emulsion. Into the reactor, 4.7 parts by mass of styrene, 1.3 parts by mass of acrylonitrile, 0.3 part by mass of potassium rosin acid, 0.1 part by mass of n-octyl mercaptan, 50 parts by mass of water, 0.15 part by mass of tert-butyl hydroperoxide and 0.02 part by mass of glucose / sodium pyrophosphate were added dropwise, the dropwise addition time was 2 h, and the reaction was kept for 1 h to prepare a first ASA emulsion.

[0082] Into a reactor, 1 part by mass of butyl acrylate, 0.002 parts by mass of sodium dodecylbenzenesulfonate, 0.2 parts by mass of divinylbenzene, 0.8 parts by mass of potassium bicarbonate and 30 parts by mass of deionized water were added, nitrogen was introduced, and the mixture was incubated at 40°C. Into the reactor, 0.002 parts by mass of sodium persulfate was added, and the reaction was carried out for 0.5 h to prepare a seed emulsion. Into the reactor, 49 parts by mass of butyl acrylate, 0.2 parts by mass of divinylbenzene, 0.15 parts by mass of sodium dodecylbenzenesulfonate, 50 parts by mass of water and 0.05 parts by mass of potassium persulfate were added dropwise, the dropwise addition was carried out for 2 h, and the reaction was incubated for 1 h to prepare a large particle size PBA emulsion. Into the reactor, 15 parts by mass of styrene, 7 parts by mass of acrylonitrile, 0.3 parts by mass of potassium disperse rosin acid, 50 parts by mass of water, 0.15 parts by mass of tert-butyl hydroperoxide and 0.02 parts by mass of glucose / sodium pyrophosphate were added dropwise, the dropwise addition was carried out for 2 h, and the reaction was incubated for 1 h to prepare a second ASA emulsion.

[0083] The two kinds of latexes were mixed to obtain a double distribution ASA latex, wherein the mass ratio of the small particle size ASA latex was 30%.

[0084] The particle sizes of the small particle size PBA latex and the large particle size PBA latex prepared in the embodiment, and the shell molecular weight of the first ASA emulsion and the second ASA emulsion are shown in Table 1.

[0085] Example 3

[0086] Into a reactor, 1 part by mass of butyl acrylate, 0.002 parts by mass of sodium dodecylbenzenesulfonate, 0.2 parts by mass of divinylbenzene, 0.8 parts by mass of potassium bicarbonate and 30 parts by mass of deionized water were added, nitrogen was introduced, and the mixture was incubated at 40°C. Into the reactor, 0.002 parts by mass of sodium persulfate was added, and the reaction was carried out for 0.5 h to prepare a seed emulsion. Into the reactor, 49 parts by mass of butyl acrylate, 0.2 parts by mass of divinylbenzene, 0.15 parts by mass of sodium dodecylbenzenesulfonate, 50 parts by mass of water and 0.05 parts by mass of potassium persulfate were added dropwise, the dropwise addition was carried out for 2 h, and the reaction was incubated for 1 h to prepare a large particle size PBA emulsion. Into the reactor, 15 parts by mass of styrene, 7 parts by mass of acrylonitrile, 0.3 parts by mass of potassium disperse rosin acid, 50 parts by mass of water, 0.15 parts by mass of tert-butyl hydroperoxide and 0.02 parts by mass of glucose / sodium pyrophosphate were added dropwise, the dropwise addition was carried out for 2 h, and the reaction was incubated for 1 h to prepare a second ASA emulsion.

[0087] Into a reactor, 4 parts by mass of butyl acrylate, 0.02 parts by mass of potassium disproportionated rosin acid, and 80 parts by mass of deionized water were added, nitrogen was introduced, and the mixture was kept at 70°C. Into the reactor, 0.02 parts by mass of ammonium persulfate was added, and the reaction was carried out for 1 h to prepare a seed emulsion. Into the reactor, 76 parts by mass of butyl acrylate, 3.8 parts by mass of triallyl isocyanurate, 0.75 parts by mass of potassium disproportionated rosin acid, 80 parts by mass of water, and 2 parts by mass of cumene hydroperoxide were added dropwise, the dropwise addition was carried out for 5 h, and the reaction was carried out for 2 h to prepare a large particle size PBA emulsion. Into the reactor, 145 parts by mass of styrene, 43 parts by mass of acrylonitrile, 1 part by mass of potassium oleate, 100 parts by mass of water, 0.5 parts by mass of cumene hydroperoxide, and 0.06 parts by mass of glucose were added dropwise, the dropwise addition was carried out for 5 h, and the reaction was carried out for 3 h to prepare a second ASA emulsion.

[0088] The two kinds of latexes were mixed to obtain a double distribution ASA latex, wherein the mass ratio of the first ASA latex was 99%.

[0089] The particle sizes of the small particle size PBA latex, the large particle size PBA latex, the shell molecular weight of the first ASA emulsion, and the second ASA emulsion prepared in this example are shown in Table 1.

[0090] Example 4

[0091] Into a reactor, 2 parts by mass of butyl acrylate, 0.8 parts by mass of potassium oleate, 0.05 parts by mass of triallyl cyanurate, 0.3 parts by mass of sodium bicarbonate, and 60 parts by mass of deionized water were added, nitrogen was introduced, and the mixture was kept at 65°C. Into the reactor, 0.01 parts by mass of cumene hydroperoxide was added, and the reaction was carried out for 0.8 h to prepare a seed emulsion. Into the reactor, 65 parts by mass of butyl acrylate, 1.5 parts by mass of triallyl cyanurate, 0.4 parts by mass of potassium oleate, 70 parts by mass of water, and 1.5 parts by mass of cumene hydroperoxide were added dropwise, the dropwise addition was carried out for 4 h, and the reaction was carried out for 2 h to prepare a small particle size PBA emulsion. Into the reactor, 15.5 parts by mass of styrene, 3.5 parts by mass of acrylonitrile, 0.7 parts by mass of sodium dodecylbenzenesulfonate, 0.3 parts by mass of n-octyl mercaptan, 80 parts by mass of water, 0.2 parts by mass of diisopropylbenzene hydroperoxide, and 0.05 parts by mass of ferrous sulfate / EDTA were added dropwise, the dropwise addition was carried out for 4 h, and the reaction was carried out for 2.5 h to prepare a first ASA emulsion.

[0092] Into a reactor were added 2 parts by mass of butyl acrylate, 0.04 parts by mass of potassium oleate, 0.05 parts by mass of triallyl cyanurate, 0.3 parts by mass of sodium bicarbonate, and 60 parts by mass of deionized water, nitrogen was introduced, and the mixture was kept at 60°C. Into the reactor was added 0.01 parts by mass of cumene hydroperoxide, and the reaction was carried out for 0.8 h to prepare a seed emulsion. Into the reactor were added dropwise 65 parts by mass of butyl acrylate, 1.5 parts by mass of triallyl cyanurate, 0.4 parts by mass of potassium oleate, 70 parts by mass of water, and 1.5 parts by mass of cumene hydroperoxide, the dropwise addition was carried out for 4 h, and the reaction was carried out for 2 h to prepare a large-particle-size PBA emulsion. Into the reactor were added dropwise 50 parts by mass of styrene, 18 parts by mass of acrylonitrile, 0.7 parts by mass of sodium dodecylbenzenesulfonate, 80 parts by mass of water, 0.2 parts by mass of cumene hydroperoxide, and 0.05 parts by mass of ferrous sulfate / EDTA, the dropwise addition was carried out for 4 h, and the reaction was carried out for 2.5 h to prepare a second ASA emulsion.

[0093] The two kinds of latexes were mixed to obtain a double-distribution ASA latex, wherein the first ASA latex accounted for 70% by mass.

[0094] The particle sizes of the small-particle-size PBA latex and the large-particle-size PBA latex, and the shell molecular weights of the first ASA emulsion and the second ASA emulsion prepared in this example are shown in Table 1.

[0095] Comparative Example 1

[0096] Compared with Example 1, the difference is that no chain transfer agent was added when the small-particle-size PBA latex was grafted, and the other conditions were the same as in Example 1.

[0097] The particle sizes of the PBA latex, and the shell molecular weights of the ASA emulsion in this comparative example are shown in Table 1.

[0098] Comparative Example 2

[0099] Compared with Example 1, the difference is that the ST was 30.3 parts by mass and the acrylonitrile was 11.7 parts by mass when the first ASA emulsion was prepared, and the other conditions were the same as in Example 1.

[0100] The particle sizes of the PBA latex, and the shell molecular weights of the ASA emulsion in this comparative example are shown in Table 1.

[0101] Comparative Example 3

[0102] Compared with Example 1, the difference is that the first ASA latex accounted for 100%, and the other conditions were the same as in Example 1.

[0103] The particle sizes of the PBA latex, and the shell molecular weights of the ASA emulsion in this comparative example are shown in Table 1.

[0104] Comparative Example 4

[0105] Comparing with example 1, the difference is that the first ASA latex accounts for 0, and the others are the same as example 1.

[0106] The particle size of PBA latex, the shell molecular weight of ASA emulsion, and the size of the latex shell solubility parameter difference SP in the present comparative example are shown in Table 1.

[0107] Comparative example 5

[0108] Comparing with example 1, the difference is that the second latex is prepared by using 32 parts by mass of styrene and 10 parts by mass of acrylonitrile, and the others are the same as example 1.

[0109] The particle size of PBA latex, the shell molecular weight of ASA, and the size of the latex shell solubility parameter difference SP in the present comparative example are shown in Table 1.

[0110] According to the following steps, the ASA latex prepared in the examples and comparative examples is prepared into ASA powder, and is blended with SAN resin for extrusion injection molding into test bars for testing:

[0111] 1) Preparation of ASA powder

[0112] 2 kg of calcium chloride, 200 kg of deionized water were added to the coagulation kettle and the stirring was started to make the calcium chloride fully dissolved. The coagulation kettle was heated to 75℃, and 100 kg of ASA grafted latex prepared in step 1) was added to the coagulation kettle in a continuous feeding manner, the continuous feeding time was 1 hour. After the feeding was completed, the coagulation kettle was heated to 90℃ and kept for 1 hour. The coagulation kettle was cooled to room temperature and the coagulation slurry was filtered, washed and dehydrated to obtain ASA wet powder. The ASA wet powder was dried in a fluidized bed dryer at 65℃ until the water content was <1% to obtain ASA powder.

[0113] 2) Preparation of ASA resin, injection molding and performance testing

[0114] A twin-screw extruder was used, and the three-stage temperature was 190℃, 210℃ and 220℃ respectively. LG Chemical SAN resin with model number SA30 was used as the blending continuous phase, and the ASA powder prepared in step 2) was used as the blending dispersed phase. The amount of SAN resin was 60 parts, and the amount of ASA powder was 40 parts. The blending extrusion and granulation were carried out to obtain the ASA resin.

[0115] The above ASA resin was used to prepare various test bars on an injection molding machine at 210℃, and the gloss and impact strength of the ASA resin were tested according to ASTM D1925 and ASTM D256 standards respectively.

[0116] Table 1 Particle size of PBA / ASA prepared in examples and comparative examples and properties of ASA resin

[0117]

[0118] From the results of Examples 1-4 and Comparative Examples 1-5, it can be seen that the ASA resins prepared using the ASA latexes of the present application have superior impact strength (>350 J / m) and higher gloss (>90) than the ASA resins prepared using the ASA latexes of the comparative examples.

[0119] Obviously, the above examples are only illustrative and not intended to limit the embodiments. Based on the above description, other different forms of changes or variations can be made by those of ordinary skill in the art. All embodiments are not required to be exhaustively listed here. The obvious changes or variations derived therefrom are still within the protection scope of the present application.

Claims

1. A dual-distribution ASA latex, characterized in that, It includes a first latex and a second latex, wherein the first latex includes a shell layer and a core layer, wherein the core layer is a polybutyl acrylate latex with an average particle size of 50nm-150nm, and the shell layer is a styrene-acrylonitrile copolymer with a mass-average molecular weight of 4w-8w. The second latex comprises a shell layer and a core layer, wherein the core layer is a polybutyl acrylate latex with an average particle size of 350nm-450nm, and the shell layer is a styrene-acrylonitrile copolymer with a mass-average molecular weight of 10w-20w.

2. The ASA latex according to claim 1, characterized in that, The difference in solubility parameter SP between the shell layers of the first latex and the shell layers of the second latex is 0.5-0.8 (cal / cm³). 3 ) 1 / 2 ; Preferably, the core-shell ratio of the first latex is 9:1-5:5, and the core-shell ratio of the second latex is 7:3-3:7; Preferably, the dual-distribution ASA latex is obtained by mixing a first latex and a second latex.

3. The ASA latex according to claim 1 or 2, characterized in that, In the ASA latex, the first latex accounts for 99wt%-30wt% by mass, preferably 70wt%-50wt% by mass, and the second latex accounts for 1wt%-70wt% by mass, preferably 30wt%-50wt% by mass.

4. The ASA latex according to any one of claims 1-3, characterized in that, The first latex and the second latex were prepared independently using the following methods: S1: Add butyl acrylate, first emulsifier, first crosslinking agent, electrolyte and water to the reactor, introduce nitrogen gas, mix and keep warm; S2: The first initiator is added to the reactor to prepare a seed emulsion; S3: Add butyl acrylate, a second crosslinking agent, a second emulsifier, water, and a second initiator to the reactor and continue the reaction to prepare polybutyl acrylate latex; S4: Add styrene, acrylonitrile, a third emulsifier, a chain transfer agent, water, a third initiator, and a reducing agent to polybutyl acrylate latex, and react at the reaction temperature to prepare ASA emulsion.

5. The ASA latex according to claim 4, characterized in that, The first emulsifier and the second emulsifier may be the same or different, and are independently anionic emulsifiers, preferably one or more of sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, potassium oleate, potassium disproportionated rosinate and sodium dioctyl sulfonate; Preferably, the first emulsifier and the second emulsifier are the same.

6. The ASA latex according to claim 4, characterized in that, The first crosslinking agent and the second crosslinking agent may be the same or different, and are each independently a multifunctional monomer, preferably one or more of divinylbenzene, allyl methacrylate, ethylene glycol acrylate, 1,3-butanediol dimethacrylate, 1,4-butanediol dimethacrylate, triallyl isocyanurate, triallyl cyanurate, diallyl maleate, and dicyclopentadienyl acrylate. Preferably, the first crosslinking agent and the second crosslinking agent are the same; Preferably, the electrolyte is an inorganic salt, preferably one or more of potassium bicarbonate, potassium carbonate, sodium bicarbonate, sodium carbonate, and sodium tripolyphosphate; Preferably, the amounts of each component added in S1 are: 1-4 parts by weight of acrylate, 0.002-2 parts by weight of emulsifier, 0-0.2 parts by weight of crosslinking agent, 0-0.8 parts by weight of electrolyte, and 30-80 parts by weight of water; Preferably, the insulation temperature in S1 is 40℃-70℃.

7. The ASA latex according to any one of claims 4-6, characterized in that, The first initiator in S2 is selected from inorganic peroxides and / or organic peroxides, preferably one or more of potassium persulfate, sodium persulfate, ammonium persulfate, dicumyl peroxide, and cumyl hydroperoxide. Preferably, the reaction time in S2 is 0.5-1 hour; Preferably, the amount of the first initiator added in S2 is 0.002-0.02 parts by weight.

8. The ASA latex according to any one of claims 4-7, characterized in that, The amounts of each component added in S3 are as follows: 49-76 parts by weight of butyl acrylate, 0.15-0.75 parts by weight of the second emulsifier, 0.2-3.8 parts by weight of the second crosslinking agent, 50-80 parts by weight of water, and 0.05-2 parts by weight of the second initiator; Preferably, the second initiator in S3 is selected from inorganic peroxides and / or organic peroxides, and more preferably one or more of potassium persulfate, sodium persulfate, ammonium persulfate, dicumyl peroxide, and cumyl hydroperoxide. Preferably, the dripping time in S3 is 2-5 hours; Preferably, the heat preservation time in S3 is 1-2 hours; Preferably, the reaction temperature in S3 is 40℃-70℃; preferably, the reaction temperatures of S3 and S1 are the same. Preferably, in S4, the third emulsifier is 0.3-1 parts by weight, the chain transfer agent is 0-0.5 parts by weight, the water is 50-100 parts by weight, the third initiator is 0.15-0.5 parts by weight, and the reducing agent is 0.02-0.06 parts by weight; Preferably, the third emulsifier in S4 is an anionic emulsifier, preferably one or more of sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, potassium oleate, potassium disproportionated rosinate, and sodium dioctyl sulfonate. Preferably, the chain transfer agent in S4 is selected from alkyl thiols, and more preferably one or more of n-octyl thiols, tert-dodecyl thiols, and n-dodecyl thiols. Preferably, the third initiator in S4 is selected from organic peroxides, and more preferably one or more of tert-butyl hydroperoxide, dicumyl peroxide, and cumyl hydroperoxide. Preferably, the reducing agent in S4 is one or more selected from ferrous sulfate, glucose, sodium pyrophosphate, sodium formaldehyde sulfoxylate, and disodium EDTA. Preferably, the addition time of each component in S4 is 2-5 hours; Preferably, the heat preservation time in S4 is 1-3 hours; Preferably, the reaction temperature in S4 is 40℃-70℃, and preferably, the reaction temperatures of S4 and S3 are the same.

9. The use of ASA latex according to any one of claims 1-8, wherein ASA latex is prepared into ASA powder, mixed with thermoplastic resin, and extruded to obtain ASA resin.

10. The use of the ASA resin according to claim 9, wherein the ASA resin is applied in the fields of automobiles, home appliances, and office supplies, preferably in the automotive field.

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