Bulk-process ASA (acrylonitrile-styrene-acrylate) resin and preparation method thereof

Abstract

The invention discloses bulk ASA resin and a preparation method thereof, and belongs to the technical field of high polymer materials. Acrylics and acrylonitrile are copolymerized to form a rubber phase, and then the rubber phase is copolymerized with styrene and acrylonitrile to form a resin phase, and the resin is prepared from the following components in percentage by mass: 10.0 to 30.0 percent of acrylate copolymerized acrylonitrile rubber, 52.5 to 67.5 percent of styrene and 17.5 to 22.5 percent of acrylonitrile. The preparation method comprises the following steps: mixing an acrylate monomer, an acrylonitrile monomer, an initiator, a molecular weight regulator and a solvent, and carrying out a copolymerization reaction to form a rubber phase; secondly, continuously adding a styrene monomer, an acrylonitrile monomer, an initiator and a molecular weight regulator, and carrying out deep polymerization reaction to form an SAN resin phase, so as to obtain an ASA resin crude product; and finally, carrying out post-treatment to obtain pure ASA resin. The ASA resin with excellent mechanical properties, thermal properties and processable flowability is synthesized through a one-pot in-situ bulk polymerization method, the processing flowability is good, low emission is achieved, industrial production is easy to achieve, and most application fields are met.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of high polymer materials, and relates to a bulk method ASA resin and a preparation method thereof. BACKGROUND

[0002] The ASA resin is composed of acrylate rubber, styrene and acrylonitrile, belongs to a typical two-phase three-component system, and is a white opaque thermoplastic resin. The biggest difference from the ABS resin is that the acrylate rubber with a saturated carbon chain is used to replace the polybutadiene rubber with an unsaturated carbon chain, so that the weather resistance and heat-oxygen aging resistance of the ASA resin are improved by several times compared with the ABS resin, and other processing properties, electrical insulation, chemical corrosion resistance and the like are similar to the ABS resin. However, this also leads to the fact that only a small amount of grafting exists in the ASA resin, so that the compatibility is poor, the mechanical properties are lower than those of the ABS resin, and the use requirements of high mechanical properties and outdoor weather resistance cannot be met at the same time.

[0003] In recent years, with the development of the ASA resin synthesis technology, the products on the market are mainly prepared by the emulsion grafting blending method, that is, ASA powder is prepared by emulsion grafting, and then is blended with SAN resin to obtain the ASA resin. At present, the acrylate rubber in most methods is prepared by emulsion polymerization, and a large amount of additives are used, so that there are many impurities in the product, which affects the performance of the product. Moreover, the separation and purification and operation cost are high in the step-by-step polymerization, so how to synthesize the ASA resin with good performance by a relatively simple method is a great technical problem. SUMMARY

[0004] In view of the problems in the prior art, the application provides a bulk method ASA resin and a preparation method thereof. Based on the strategy of "supramolecular physical action-molecular polarity optimization", the ASA resin with excellent mechanical properties, thermal properties and processability is synthesized by a one-pot in-situ bulk polymerization method. The dipole-dipole interaction is formed between the cyano groups of the SAN resin phase and the P(BA-co-AN) rubber phase by the stepwise feeding mode, and the compatibilized ASA resin has excellent mechanical properties and heat resistance and excellent processability. Meanwhile, the one-pot in-situ bulk method overcomes the problems of segmented discharge and complex operation process, realizes the synthesis of the rubber and the resin by one set of device, and does not need to replace the solvent.

[0005] To achieve the above object, the application adopts the following technical scheme:

[0006] The application provides a bulk ASA resin, which is formed by copolymerization of acrylate and acrylonitrile to form a rubber phase, acrylate copolymerized acrylonitrile rubber is obtained, and then copolymerization of styrene and acrylonitrile is performed to form a resin phase, and the specific content of each component is as follows: the acrylate copolymerized acrylonitrile rubber is 10.0-30.0%, the styrene is 52.5-67.5%, and the acrylonitrile is 17.5-22.5%.

[0007] Further, the relative molecular weight of the ASA resin is 1.2*10 5 -1.8*10 5 g / mol, preferably 1.4*10 5 -1.6*10 5 g / mol.

[0008] Further, the acrylate copolymerized acrylonitrile rubber is formed by free radical copolymerization of acrylate and acrylonitrile, and the copolymer sequence structure has random sequence and alternating sequence; the relative molecular weight is 1.1*10 5 -1.6*10 5 g / mol, more preferably 1.2*10 5 -1.5*10 5 g / mol. The mass ratio of acrylate to acrylonitrile is 90:10-70:30.

[0009] The application further provides a preparation method of the ASA resin.

[0010] Firstly, acrylate copolymerized acrylonitrile rubber is prepared.

[0011] Under the protection of inert atmosphere, acrylate monomers, acrylonitrile monomers, initiators, molecular weight regulators and a small amount of solvent are mixed and then copolymerized, acrylate monomers and acrylonitrile monomers are copolymerized to form a rubber phase, in this step, the initiators generate primary free radicals to attack acrylate monomers and acrylonitrile monomers to form monomer free radicals, and then the monomer free radicals attack the two different monomers to gradually form copolymer rubber.

[0012] Further, the copolymerization temperature is 60-80°C, and the copolymerization time is 4-6h.

[0013] Further, the mass ratio of acrylate monomers to acrylonitrile monomers is 90:10-70:30, preferably 85:15-75:25.

[0014] Further, the solvent includes one or a mixture of several of xylene, ethylbenzene and toluene, preferably toluene; the mass of the solvent is 8-25% of the total mass of the acrylate monomers and acrylonitrile monomers, preferably 10-20%.

[0015] Further, the acrylate monomers are one or a mixture of several of methyl acrylate, ethyl acrylate, butyl acrylate, isooctyl acrylate or butyl methacrylate, preferably butyl acrylate.

[0016] Further, the initiator includes one or a mixture of several of dibenzoyl peroxide, azobisisobutyronitrile, di-tert-butyl peroxide and 1,1-di-(tert-butylperoxy)cyclohexane, preferably azobisisobutyronitrile. The mass of the initiator is 0.01-0.25% of the total mass of the acrylate monomers and acrylonitrile monomers, preferably 0.08-0.14%.

[0017] Further, the molecular weight regulator is one or a mixture of several of n-dodecyl mercaptan, tert-dodecyl mercaptan and ethanedithiol, preferably tert-dodecyl mercaptan. The mass of the molecular weight regulator is 0.05-0.3% of the total mass of the acrylate monomers and acrylonitrile monomers, preferably 0.1-0.18%.

[0018] Second step, preparation of ASA resin crude product with dipole-dipole interaction compatibilization;

[0019] Under the protection of inert gas, the styrene monomer, acrylonitrile monomer, initiator and molecular weight regulator are continuously added to the first step reactor to carry out deep polymerization reaction to form SAN resin phase, and ASA resin crude product is obtained. In this step, after the formation of SAN resin phase, a supramolecular interaction is formed between the cyano group of polyacrylonitrile in the P(BA-co-AN) rubber phase and the positive and negative charges due to the mutual attraction, that is, through the molecular optimization strategy of introducing AN into the rubber phase, the ASA resin crude product with dipole-dipole interaction compatibilization is obtained.

[0020] Further, the temperature of the polymerization reaction is 60-80℃, and the time is 3-5h. Among them, the polymerization reaction temperature is the same as the first step.

[0021] Further, the solvent includes one or a mixture of several of xylene, ethylbenzene and toluene, preferably toluene; the mass of the solvent is 8-25% of the total mass of the acrylate monomers and acrylonitrile monomers, preferably 10-20%.

[0022] Further, the initiator comprises one or several mixtures of dibenzoyl peroxide, azobisisobutyronitrile, di-tert-butyl peroxide and 1,1-di-(tert-butylperoxy)cyclohexane, preferably azobisisobutyronitrile. The mass of the initiator is 0.01-0.25% of the total mass of the acrylate monomers and the acrylonitrile monomers, preferably 0.08-0.14%.

[0023] Further, the molecular weight regulator comprises one or several mixtures of n-dodecyl mercaptan, tert-dodecyl mercaptan and ethanedithiol, preferably tert-dodecyl mercaptan. The mass of the molecular weight regulator is 0.05-0.3% of the total mass of the acrylate monomers and the acrylonitrile monomers, preferably 0.1-0.18%.

[0024] Thirdly, the ASA resin crude prepared in the second step is post-treated to obtain pure ASA resin;

[0025] The post-treatment process is as follows: firstly, the ASA resin crude obtained in the second step is cut into small pieces and placed in a vacuum oven for devolatilization to remove the residual solvent and monomers in the reaction, wherein the devolatilization temperature is 80-100°C and the time is 18-24h; then, the small pieces of the ASA resin crude after devolatilization are further treated by using a double-screw vacuum exhaust extruder, which is heated to 180-220°C and subjected to high vacuum treatment for 20-30s to promote the exchange of internal substances of the ASA resin crude, and finally pure ASA resin is obtained. The high vacuum is-0.095 to-0.1MPa. During the heating and high vacuum treatment in this step, the small pieces of the ASA resin crude are first heated to melt, which significantly reduces the viscosity, and the high vacuum greatly reduces the boiling point of the volatile components, and this process mainly removes the oligomers in the crude.

[0026] The beneficial effects of the present application are as follows:

[0027] (1) The present application uses the strategy of "supramolecular physical action-molecular polarity optimization", and forms a dipole-dipole interaction between the two phases of the ASA resin by introducing acrylonitrile into the acrylate rubber, which plays a compatibilization effect, solves the problems of low mechanical properties caused by poor interfacial compatibility of the two phases of the ASA resin and high gel content caused by grafting and crosslinking, and maintains the high weather resistance of the ASA resin itself; that is, the dipole-dipole interaction compatibilized ASA resin provided by the present application has excellent mechanical properties and weather resistance, and does not produce gel, and has good processing fluidity.

[0028] (2) The ASA resin is prepared by one-pot in-situ bulk method, the preparation method is simple and easy to implement, the problems of a large amount of "three wastes" and complex step-by-step polymerization operation in the synthesis of ASA resin by emulsion polymerization method are optimized, low emission and good economic benefits are realized; at the same time, the segmented feeding solves the problems of complex conventional operation process and long time consumption; in addition, the bulk polymerization method optimizes the problems of high production cost and more impurities in the synthesis of ASA resin by the commonly used emulsion method, realizes low emission and easy industrialization production, and meets most application fields. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 P(BA-co-AN) prepared in Example 3 8:2 Fourier transform infrared spectra of the rubber and the toughened ASA resin thereof.

[0030] Figure 2 P(BA-co-AN) prepared in Example 3 8:2 GPC spectra of the rubber and the toughened ASA resin thereof.

[0031] Figure 3 P(BMA-co-AN) prepared in Example 5 8:2 Fourier transform infrared spectra of the rubber and the toughened ASA resin thereof.

[0032] Figure 4 SEM diagram of impact section of the ASA resin of Example 2. DETAILED DESCRIPTION

[0033] The technical solutions of the present application will be described clearly and completely below in combination with the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application. Unless otherwise specified, the present application has no special requirements for the source of the raw materials used, and commercially available goods known to those skilled in the art can be used.

[0034] Example 1 (based on a total mass of 100g)

[0035] (1) 8.0g of ethyl acrylate, 2.0g of acrylonitrile, 0.001g of azobisisobutyronitrile, 0.003g of ethanedithiol and 0.8g of toluene were added to a reactor maintained in an inert atmosphere, the mass ratio of ethyl acrylate to acrylonitrile was 80:20, and the reaction was carried out at 75℃ for 5h to form a rubber phase;

[0036] (2) Continue to add 67.5 g of styrene, 22.5 g of acrylonitrile, 0.009 g of azobisisobutyronitrile, 0.27 g of ethanedithiol, and 7.2 g of toluene to carry out the polymerization reaction for 3.5 h to form a SAN resin phase, to obtain a crude ASA resin compatibilized by dipole-dipole interaction;

[0037] (3) After the reaction is completely finished, the ASA resin is cut into small pieces and placed in a vacuum oven at 80°C for 24 h to remove small molecule solvents and monomers by devolatilization; then the cut ASA resin pieces are further treated using a twin-screw vacuum vented extruder, heated to 180°C and applied with a high vacuum of -0.095 MPa, the dried ASA particles are placed therein for 30 s to promote internal mass exchange, and finally a pure ASA resin is obtained.

[0038] Example 2 (in terms of 100 g of total mass)

[0039] (1) In a reactor maintained in an inert atmosphere, 21 g of methyl acrylate, 9 g of acrylonitrile, the mass ratio of methyl acrylate to acrylonitrile being 70:30, 0.075 g of di-tert-butyl peroxide, 0.03 g of n-dodecyl mercaptan, and 4.5 g of ethylbenzene are added, and reacted at 60°C for 6 h to form a rubber phase;

[0040] (2) Continue to add 52.5 g of styrene, 17.5 g of acrylonitrile, 0.175 g of di-tert-butyl peroxide, 0.07 g of n-dodecyl mercaptan, and 10.5 g of ethylbenzene to carry out the polymerization reaction for 5 h to form a SAN resin phase, to obtain a crude ASA resin compatibilized by dipole-dipole interaction;

[0041] (3) After the reaction is completely finished, the ASA resin is cut into small pieces and placed in a vacuum oven at 95°C for 21 h to remove small molecule solvents and monomers by devolatilization; then the cut ASA resin pieces are further treated using a twin-screw vacuum vented extruder, heated to 220°C and applied with a high vacuum of -0.1 MPa, the dried ASA particles are placed therein for 20 s to promote internal mass exchange, and finally a pure ASA resin is obtained.

[0042] Example 3 (in terms of 100 g of total mass)

[0043] (1) In a reactor maintained in an inert atmosphere, 20 g of butyl acrylate, 5 g of acrylonitrile, the mass ratio of butyl acrylate to acrylonitrile being 80:20, 0.025 g of azobisisobutyronitrile, 0.0375 g of tert-dodecyl mercaptan, and 2.5 g of toluene are added, and reacted at 70°C for 5 h to form a rubber phase;

[0044] (2) Continue to add 56.25 g of styrene, 18.75 g of acrylonitrile, 0.075 g of azobisisobutyronitrile, 0.1125 g of tert-dodecyl mercaptan, and 7.5 g of toluene to carry out the polymerization reaction for 3.5 h to form a SAN resin phase, to obtain a crude ASA resin compatibilized by dipole-dipole interaction;

[0045] (3) After the reaction is completely finished, cut the ASA resin into small pieces and place them in a vacuum oven at 100 °C for 18 h to remove small molecule solvents and monomers by devolatilization; then further process the cut ASA resin pieces using a twin-screw vacuum vented extruder, heat to 190 °C and apply a high vacuum of -0.097 MPa, place the dried ASA particles in it for 25 s to promote internal mass exchange, and finally obtain a pure ASA resin.

[0046] Example 4 (in terms of 100 g total mass)

[0047] (1) In a reactor maintained in an inert atmosphere, add 27 g of butyl acrylate, 3 g of acrylonitrile, the mass ratio of butyl acrylate to acrylonitrile being 90:10, 0.075 g of dibenzoyl peroxide, 0.15 g of n-dodecyl mercaptan, and 7.5 g of xylene, and react at 65 °C for 4 h to form a rubber phase;

[0048] (2) Continue to add 52.5 g of styrene, 17.5 g of acrylonitrile, 0.175 g of dibenzoyl peroxide, 0.035 g of n-dodecyl mercaptan, and 17.5 g of xylene to carry out the polymerization reaction for 5 h to form a SAN resin phase, to obtain a crude ASA resin compatibilized by dipole-dipole interaction;

[0049] (3) After the reaction is completely finished, cut the ASA resin into small pieces and place them in a vacuum oven at 95 °C for 22 h to remove small molecule solvents and monomers by devolatilization; then further process the cut ASA resin pieces using a twin-screw vacuum vented extruder, heat to 200 °C and apply a high vacuum of -0.096 MPa, place the dried ASA particles in it for 28 s to promote internal mass exchange, and finally obtain a pure ASA resin.

[0050] Example 5 (in terms of 100 g total mass)

[0051] (1) In a reactor maintained in an inert atmosphere, add 16 g of butyl methacrylate, 4 g of acrylonitrile, the mass ratio of butyl methacrylate to acrylonitrile being 80:20, 0.03 g of azobisisobutyronitrile, 0.02 g of tert-dodecyl mercaptan, and 4 g of ethylbenzene, and react at 80 °C for 4 h to form a rubber phase;

[0052] (2) 60 g of styrene, 20 g of acrylonitrile, 0.12 g of azobisisobutyronitrile, 0.08 g of tert-dodecyl mercaptan, and 16 g of ethylbenzene were added to carry out polymerization for 4 h to form a SAN resin phase, thereby obtaining a crude ASA resin product with dipole-dipole interaction compatibilization;

[0053] (3) After the reaction is complete, the ASA resin is cut into small pieces and placed in an 85°C vacuum oven for 20 hours to devolatilize the small molecule solvent and monomer; then the chopped ASA resin pieces are further processed using a twin-screw vacuum exhaust extruder, the temperature is raised to 210°C and a high vacuum of -0.098 MPa is applied, and the dried ASA particles are placed in it for 24 seconds to promote internal material exchange, and finally pure ASA resin is obtained.

[0054] Comparative Example 1

[0055] (1) Preparation of polybutyl acrylate seeds;

[0056] First, distilled water was added to a three-necked flask, nitrogen was passed through, the temperature was controlled at 70°C, and butyl acrylate was emulsion polymerized using sodium lauryl sulfate as an emulsifier and potassium persulfate as an initiator to prepare seeds.

[0057] (2) Preparation of polybutyl acrylate core;

[0058] Place a certain amount of seed emulsion into a three-necked flask equipped with a stirrer, dilute with distilled water to the desired dilution, add a portion of emulsifier, and add a certain amount of sodium bisulfite formaldehyde solution. Control the temperature at 60°C, then dropwise add a pre-prepared pre-emulsion containing cumene hydroperoxide, a crosslinker, a grafting agent, butyl acrylate, and an emulsifier to produce polybutyl acrylate rubber particles through seed emulsion polymerization.

[0059] (3) Preparation of grafted powder;

[0060] A pre-prepared pre-emulsion containing cumene hydroperoxide, styrene, acrylonitrile, and an emulsifier is continuously added dropwise to a polybutyl acrylate emulsion to which a reducing agent has been added, and polymerization is continued to produce an ASA emulsion. The ASA emulsion is diluted with distilled water, heated to 80°C, and demulsified with an aqueous solution of magnesium sulfate. The powder is then washed, filtered, and dried to produce an ASA core-shell graft polymer powder, which is then blended with SAN resin to produce an ASA resin.

[0061] (4) Preparation of ASA resin;

[0062] The ASA grafted powder was dried at 80°C for 4 hours, and the SAN resin was dried at 85°C for 2 hours. The ASA grafted powder and the SAN resin were blended at 170°C using a two-roll mill to prepare the ASA resin.

[0063] Comparative Example 2 (in terms of 100 g total mass)

[0064] (1) 30 g of butyl acrylate, 0.03 g of azobisisobutyronitrile, 0.145 g of tert-dodecyl mercaptan, and 3 g of toluene were added to a reactor maintained in an inert atmosphere, and reacted at 70°C for 5 h to form a rubber phase;

[0065] (2) 52.5 g of styrene, 17.5 g of acrylonitrile, 0.07 g of azobisisobutyronitrile, 0.105 g of tert-dodecyl mercaptan, and 7 g of toluene were continuously added to polymerize for 3.5 h to form a SAN resin phase, to obtain a crude ASA resin;

[0066] (3) After the reaction was completed, the ASA resin was cut into small pieces and placed in a 100°C vacuum oven for 24 h to remove small molecule solvents and monomers by devolatilization; then the cut ASA resin pieces were further processed using a twin-screw vacuum vented extruder, heated to 190°C and applied with a high vacuum of -0.097 MPa, and the dried ASA particles were placed therein for 25 s to promote internal mass exchange, and finally a pure ASA resin was obtained.

[0067] The properties of the products prepared in the examples and comparative examples were tested and characterized as follows:

[0068] Test 1: Fourier Transform Infrared Spectroscopy (FTIR)

[0069] The structure of the polymer was analyzed by Fourier Transform Infrared Spectrometer (FTIR, Thermo Fisher iS50, USA), with a spectral range of 4500-400 cm -1 , and a resolution of 4 cm -1 .

[0070] Test 2: Gel Permeation Chromatography (GPC)

[0071] The relative molecular weight (Mn, Mw) and molecular weight distribution (PDI) of the polymer were determined by Waters 1515 high performance liquid chromatography. THF was used as the eluent, the flow rate was 1.0 ml / min, the temperature was 30°C, and a polystyrene standard was used to establish a molecular weight calibration curve.

[0072] Test 3: Scanning Electron Microscopy (SEM)

[0073] The impact fracture morphology of the ASA resin was observed by SU8220 scanning electron microscope. Before measurement, the sample surface was gold plated.

[0074] Figure 1 is P(BA-co-AN) in Example 3 8:2 Fourier transform infrared spectra of the rubber and the ASA resin, first P(BA-co-AN)8:2 1730 and 1166cm -1 Strong bands appeared, which were the stretching vibration peaks of -C=O and -CO in the PBA component, 2930 and 2871 cm -1 The absorption band at 2238 cm is attributed to the saturated -CH group; -1 The peaks are attributed to the stretching vibration peak of -C≡N, which proves that AN is successfully introduced into BA. In addition to the peak positions of the above groups, the infrared curve of ASA also has peaks at 1632, 1602 and 1493 cm -1 The absorption band at corresponds to the stretching vibration of the benzene ring skeleton. Figure 3 The same is true for the peak position when ASA resin is toughened with P(BMA-co-AN) rubber.

[0075] Figure 2 This is the GPC curve of Example 3. It can be seen from the GPC curve that P(BA-co-AN) 8：2 The number average molecular weight Mn of rubber is 1.43×10 5 g / mol, and the weight average molecular weight Mw is 2.59×10 5 g / mol, the polydispersity index PDI is 1.81, and the molecular weight is moderate. If the molecular weight is too high, the melt viscosity will be large, which may cause injection molding or extrusion difficulties. If it is too low, the molecular chain will be short, which may cause insufficient strength of the rubber phase itself and weaken the toughening effect. The number average molecular weight Mn of ASA resin is 1.5×10 5 g / mol, and the weight average molecular weight Mw is 2.94×10 5 g / mol, the polydispersity index PDI is 1.96, and the molecular weight and distribution are also relatively moderate.

[0076] Figure 4 The SEM morphology of the impact cross section of Example 2 shows that the surface of the material exhibits highly developed silver streaks and cavitation phenomena. It is the synergistic effect of these two that significantly improves the energy dissipation capacity of the material and exhibits a good toughening effect.

[0077] Test 3: simply supported beam impact test;

[0078] With reference to ISO 179, the samples of Example 3 and Comparative Examples 1-2 were injection molded into 80 mm × 10 mm × 4 mm (± 0.2 mm) long, wide, and thick bars using a Thermo Scientific MiniJet Pro injection molding machine, with 5 bars in each group. The bars were subjected to a simply supported beam impact test using a Taiwan High Speed ​​Rail Corporation AI-7000M-2 impact testing machine with a pendulum energy of 4.5 J and a test temperature of 23° C.

[0079] Test 4: tensile properties test;

[0080] The tensile properties of Example 3 and Comparative Examples 1-2 were tested by using a universal material testing machine according to ISO 527 standard. The sample size was 75 mm x 4 mm x 2 mm (±0.2 mm), the tensile speed was 5 mm / min, and the test temperature was 23°C.

[0081] The gloss of Example 3 and Comparative Examples 1-2 was tested by using a YG568 gloss meter according to ASTM D523-2008 standard at an angle of 60°.

[0082] The MFR of Example 3 and Comparative Examples 1-2 was tested by using an XNR-400 melt flow rate instrument according to ASTM D1238 standard at a test temperature of 220°C and a nominal load of 10 kg. The MFR was calculated from the average mass (Wg) of 10 segments cut from each sample and the time interval t (s) of cutting the sample.

[0083] The Vicat softening temperature of Example 3 and Comparative Examples 1-2 was tested by using an XRW-300 series Vicat softening point temperature tester according to ISO 306 standard. The load used for the test should be 1 kg (10 N), and the test temperature rise rate was 50°C / h.

[0084] The gel fraction of the polymer was measured by a weighing method. A certain amount of polymer sample was extracted with a Soxhlet extractor in a 80°C oil bath for 48 h using THF as the solvent, and the residue was completely dried under vacuum. The gel fraction was calculated from the mass difference before and after drying.

[0085] Table 1 Comprehensive properties of the ASA resins obtained in Example 3 and Comparative Examples 1-2

[0086]

[0087] Table 1 is the various property test data of Example 3 and Comparative Examples 1-2. As can be seen from the data in the table, the impact strength, tensile properties, Vicat softening temperature, gloss, and melt index of the ASA resin obtained in Example 3, which is compatibilized by dipole-dipole interaction, are all higher than those of the ASA resin of Comparative Example 2, which is toughened by pure PBA rubber. The formulation of Example 3 is P(BA-co-AN) rubber with a BA:AN ratio of 80:20, and the content of P(BA-co-AN) in the ASA resin is 25%. The properties of the obtained ASA resin are the best, with a Charpy impact strength of 79.9 KJ / m2 and an elongation at break of 47.8%, which indicates that the cyano-to- intermolecular dipole-dipole interaction significantly improves the properties of the ASA resin. 8:2 In the ASA resin, the content of P(BA-co-AN) is 25%, and the properties of the obtained ASA resin are the best, with a Charpy impact strength of 79.9 KJ / m2 and an elongation at break of 47.8%, which indicates that the cyano-to- intermolecular dipole-dipole interaction significantly improves the properties of the ASA resin.

[0088] In addition, compared with the ASA resin produced by the emulsion method of Comparative Example 1, the mechanical properties and thermal properties of Example 3 are comparable; at the same time, the melt index of the ASA resin obtained by the dipole-dipole interaction compatibilization of the patent is higher than that of Comparative Example 1, which benefits from the fact that the supramolecular physical interaction does not produce gel, i.e. excellent processing fluidity, which is particularly suitable for the application of fine and thin-walled outdoor products.

[0089] In summary, the ASA resin and the preparation method thereof described in the present application adopt a one-pot in-situ bulk method to obtain an ASA resin with dipole-dipole interaction between two phases. The P(BA-co-AN) copolymer and the ASA resin are characterized by Fourier transform infrared spectroscopy and gel permeation chromatography analysis. 8:2 The rubber and the ASA resin are characterized; at the same time, the Charpy impact test and the tensile property test show that the obtained ASA resin has excellent mechanical properties; the Vicat softening temperature test shows that the ASA resin has good thermal properties; the melt index and gel rate test show that the obtained ASA resin has excellent processing fluidity. In summary, the ASA resin with dipole-dipole interaction compatibilization obtained by the one-pot in-situ bulk method has good comprehensive properties.

[0090] The above describes the specific embodiments of the present application in combination with the drawings, but is not a limitation on the protection scope of the present application, and those skilled in the art should understand that various modifications or changes made by those skilled in the art on the basis of the technical solutions of the present application without creative labor are still within the protection scope of the present application.

Claims

1. A bulk ASA resin, characterized in that, The bulk ASA resin is prepared by copolymerizing acrylates and acrylonitrile to form a rubber phase to obtain acrylate copolymerized polyacrylonitrile rubber, which is then copolymerized with styrene and acrylonitrile to form a resin phase. The specific contents of each component, in terms of mass percentage, are as follows: 10.0-30.0% of the acrylate copolymerized polyacrylonitrile rubber, 52.5-67.5% of the styrene, and 17.5-22.5% of the acrylonitrile.

2. A bulk ASA resin according to claim 1, characterized in that, The acrylic ester copolymerized polyacrylonitrile rubber is formed by free radical copolymerization of acrylic ester and acrylonitrile, and the copolymer sequence structure has both random sequence and alternating sequence; wherein the mass ratio of acrylic ester to acrylonitrile is 90:10 to 70:

30.

3. A bulk ASA resin according to claim 1, characterized in that, The relative molecular weight of the ASA resin is 1.2×10 5 ~1.8×10 5 The relative molecular mass of the acrylic copolymerized polyacrylonitrile rubber is 1.1×10 5 ~1.6×10 5 g / mol.

4. A bulk ASA resin according to claim 1, characterized in that, The relative molecular weight of the ASA resin is 1.4×10 5 ~1.6×10 5 The relative molecular mass of the acrylic copolymerized polyacrylonitrile rubber is 1.2×10 5 ~1.5×10 5 g / mol.

5. A method for preparing a bulk ASA resin according to any one of claims 1 to 4, characterized in that: The following steps are involved: The first step is to prepare acrylic copolymerized polyacrylonitrile rubber; Under the protection of an inert atmosphere, acrylic acid ester monomer, acrylonitrile monomer, initiator, molecular weight regulator and solvent are added into a reactor and mixed to carry out copolymerization reaction, whereby the acrylic acid ester monomer and acrylonitrile monomer copolymerize to form a rubber phase; The second step is to prepare a crude ASA resin compatibilized by dipole-dipole interaction; Under the protection of inert gas, styrene monomer, acrylonitrile monomer, initiator, and molecular weight regulator are continuously added to the first step reactor to carry out deep polymerization reaction to form SAN resin phase and obtain ASA resin crude product; The third step is to post-treat the crude ASA resin prepared in the second step to obtain pure ASA resin.

6. The preparation method of bulk ASA resin according to claim 5, wherein In the first step, the copolymerization reaction temperature is 60-80° C. and the time is 4-6 hours; in the second step, the polymerization reaction temperature is the same as that in the first step and the time is 3-5 hours.

7. The method for preparing a bulk ASA resin according to claim 5, wherein: In the first step, the mass ratio of the acrylic acid ester monomer to the acrylonitrile monomer is 90:10 to 70:30; The solvent comprises one or a mixture of xylene, ethylbenzene and toluene, and the mass of the solvent is 8 to 25% of the total mass of the acrylic acid ester monomer and the acrylonitrile monomer; The acrylic acid ester monomer is one or a mixture of methyl acrylate, ethyl acrylate, butyl acrylate, isooctyl acrylate or butyl methacrylate; The initiator comprises one or a mixture of dibenzoyl peroxide, azobisisobutyronitrile, di-tert-butyl peroxide and 1,1-di(tert-butylperoxy)cyclohexane; the mass of the initiator is 0.01 to 0.25% of the total mass of the acrylic ester monomer and the acrylonitrile monomer; The molecular weight regulator is one or a mixture of n-dodecyl mercaptan, tert-dodecyl mercaptan and ethanedithiol; the mass of the molecular weight regulator is 0.05-0.3% of the total mass of the acrylic acid ester monomer and the acrylonitrile monomer; In the second step: The solvent comprises one or a mixture of xylene, ethylbenzene and toluene; the mass of the solvent is 8 to 25% of the total mass of the acrylic ester monomer and the acrylonitrile monomer; The initiator comprises one or a mixture of dibenzoyl peroxide, azobisisobutyronitrile, di-tert-butyl peroxide and 1,1-di(tert-butylperoxy)cyclohexane; the mass of the initiator is 0.01 to 0.25% of the total mass of the acrylic ester monomer and the acrylonitrile monomer; The molecular weight regulator is one or a mixture of n-dodecyl mercaptan, tert-dodecyl mercaptan and ethanedithiol; the mass of the molecular weight regulator is 0.05-0.3% of the total mass of the acrylic acid ester monomer and the acrylonitrile monomer.

8. The method for preparing a bulk ASA resin according to claim 5, wherein: In the first step: The mass ratio of the acrylic acid ester monomer to the acrylonitrile monomer is preferably 85:15 to 75:25; The solvent is preferably toluene; the mass of the solvent is preferably 10 to 20% of the total mass of the acrylic acid ester monomer and the acrylonitrile monomer; The acrylic acid ester monomer is preferably butyl acrylate; The initiator is preferably azobisisobutyronitrile; the mass of the initiator is preferably 0.08 to 0.14% of the total mass of the acrylate monomer and the acrylonitrile monomer; The molecular weight regulator is preferably tert-dodecyl mercaptan; the mass of the molecular weight regulator is preferably 0.1 to 0.18% of the total mass of the acrylic acid ester monomer and the acrylonitrile monomer; In the second step: The solvent is preferably toluene; the mass of the solvent is preferably 10 to 20% of the total mass of the acrylic acid ester monomer and the acrylonitrile monomer; The initiator is preferably azobisisobutyronitrile; the mass of the initiator is preferably 0.08 to 0.14% of the total mass of the acrylate monomer and the acrylonitrile monomer; The molecular weight regulator is preferably tert-dodecyl mercaptan; the mass of the molecular weight regulator is preferably 0.1 to 0.18% of the total mass of the acrylic acid ester monomer and the acrylonitrile monomer.

9. The method for preparing a bulk ASA resin according to claim 5, wherein The third post-processing process is as follows: First, the crude ASA resin obtained in the second step is cut into small pieces and placed in a vacuum oven for devolatilization to remove residual solvent and monomers from the reaction; then, the devolatilized crude ASA resin is further processed using a twin-screw vacuum exhaust extruder, heating it to 180-220°C and applying high vacuum treatment for 20-30 seconds to promote the exchange of internal substances in the crude ASA resin to obtain pure ASA resin.

10. The method for preparing a bulk ASA resin according to claim 9, wherein: The devolatilization temperature is 80-100° C., and the time is 18-24 hours; and the high vacuum is -0.095--0.1 MPa.

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