Preparation method for modified bimodal ABS special resin

Abstract

A preparation method for a modified bimodal ABS special resin, comprising: selecting a bimodal ABS (acrylonitrile-butadiene-styrene) latex and a glycidyl methacrylate (GMA) having an epoxy group and performing graft polymerization, and preparing a modified ABS resin suitable for use in multiple types of ABS alloy material.

Description

Preparation method of modified bimodal ABS special resin TECHNICAL FIELD

[0001] The present application belongs to the field of new chemical materials or polymer materials, and particularly relates to a modified bimodal ABS special resin. BACKGROUND

[0002] ABS resin is a terpolymer composed of acrylonitrile, butadiene and styrene. The structure of ABS resin is that elastomer is the main chain, and polybutadiene rubber particles in the form of acrylonitrile-butadiene-styrene terpolymer (CHT powder) are dispersed in a continuous phase system of acrylonitrile-styrene copolymer (SAN resin), forming an organic whole. Different structural ratios show different properties. Elastomer shows the toughness of rubber, and hard SAN resin shows rigidity. Therefore, high impact type, medium impact type, general impact type and special impact type and the like can be obtained by adjusting the ratio of CHT and SAN.

[0003] ABS is one of the five general synthetic resins, and its rapid development is inseparable from its internal structure composition. Styrene endows the resin with rigidity, electrical properties, easy processability and surface gloss; butadiene endows the resin with toughness and low-temperature impact resistance; acrylonitrile endows the resin with chemical resistance, weather resistance, heat resistance and tensile strength. Due to the combination of the three components, the advantages are complementary, so that ABS products can be adjusted in multiple grades according to the actual needs of production, and then become the largest resin variety in the development and change of styrene series resins.

[0004] In order to make ABS resin achieve a certain performance, ABS alloy obtained by compounding modification with other resin base materials has been widely used. Common ABS alloys include ABS / PC, ABS / PA, ABS / PBT, ABS / PVC and the like. Among them, ABS / PC is to improve the flame retardance of ABS, has good mechanical strength, toughness and flame retardance; ABS / PA has impact resistance, chemical resistance, good flowability and heat resistance; ABS / PBT has good heat resistance, strength, chemical resistance and flowability. Therefore, it is very necessary to develop a modified bimodal ABS resin for preparing various ABS alloy materials and improving the compatibility of ABS resin with other resins.

[0005] SUMMARY

[0006] Therefore, the present application provides a modified bimodal ABS special resin and a preparation method thereof, which can improve the compatibility of ABS resin with PC, PBT and the like, and ensure that the processing of ABS alloy resin is simple and excellent in performance.

[0007] It should be noted that the present application is directed to the design of the modified bimodal ABS special resin, first, the bimodal latex in the selection of ABS emulsion polymerization process, and the styrene, acrylonitrile and glycidyl methacrylate (GMA) are grafted to obtain the modified bimodal ABS special resin. In the polymerization process, the C=C double bond in the GMA molecule can be polymerized with styrene, acrylonitrile, and the epoxy group provided by GMA can be used as a functional group to participate in alloy preparation, such as forming an effective chemical bond with PBT, improving the compatibility of PBT and ABS resin, and improving the mechanical properties. In order to achieve the above purpose, the present application provides the following technical scheme:

[0008] A modified bimodal ABS special resin, mainly composed of the following substances in mass fraction:

[0009] Modified grafting powder CHT 24-33 parts, SAN resin 66-75 parts, lubricant 0.05-0.3 parts, plasticizing modifier 0.35-0.7 parts, antioxidant A 0.1-0.3 parts, antioxidant B 0.03-0.05 parts.

[0010] Optionally, the lubricant is magnesium stearate, the plasticizing modifier is ethylene butyl acrylate or EBS vinyl bis stearyl amide;

[0011] The antioxidant A is distearyl pentaerythritol diphosphite or 2,6-di-tert-butyl-4-methylphenol, and the antioxidant B is sulfurized dipropionic acid dioctadecyl ester, beta-(3,5-di-tert-butyl-4-hydroxyphenyl) octadecyl propionate, sulfurized dipropionic acid dilauryl ester;

[0012] The present application also claims the preparation method of the above-mentioned modified bimodal ABS special resin, comprising the following steps:

[0013] (1) 500g of water, 870-890g of M latex (PB latex with a particle size of 320nm-335nm), 220-240g of T latex (PB latex with a particle size of 280nm-290nm), 66-78g of ST (styrene), 24-32g of AN (acrylonitrile), and a pH value in the range of 10.6-11.4 are added to a 3L four-necked round-bottom flask, and a little emulsifier, initiator and relative molecular mass regulator TDDM are added, and then a reducing agent, sodium pyrophosphate and ferrous sulfate solution are added as reducing agents, and the polymerization reaction is carried out at 60℃ constant temperature, and the temperature is continuously increased to 70℃ at 2℃ / 10min, and the duration is 30min.

[0014] The mixed solution of St 200-220 g, AN 75-95 g and a little initiator and molecular weight regulator is dropped into the four-necked flask at a constant speed for 2 hours. Then the temperature is raised to 75°C, a little mixed solution of initiator, reducing agent and reducing agent aid is added and the reaction is continued for 30 minutes. The pH value is adjusted to keep constant, and 2.5-12.5 g of GMA is added at a constant speed for 3-13 minutes, and the reaction time is 40 minutes. Finally, a little antioxidant is added, and the reaction is aged for 40 minutes. The obtained emulsion is broken, washed, dehydrated and dried to obtain ABS modified powder.

[0015] (2) The modified grafting powder CHT prepared in step (1) is mixed with SAN resin, lubricant, plasticizing modifier, antioxidant A and antioxidant B in a high-speed mixer for 3-5 minutes, and then the blended material is added into a twin-screw extruder for melt blending, extrusion granulation and water cooling, and then cut into Φ3mm x Φ3mm cylindrical products to obtain modified bimodal ABS special resin.

[0016] Optionally, the parameters of the twin-screw extruder in (2) are set as follows:

[0017] The screw rotation speed is 220 r / min, and the extruder temperature is set as four parts of machine conveying section, plasticizing section, metering section and die temperature, wherein the machine conveying section, plasticizing section, metering section and die temperature are set as 200-210°C, 200-220°C, 210-240°C and 220-240°C respectively; at the same time, the machine is subjected to vacuum treatment, and the vacuum degree is 0.06±0.01 MPa.

[0018] It should be noted that the processing temperature has an influence on the mixing degree of the modified grafting powder CHT and SAN resin and the performance index of the ABS resin.

[0019] According to the above technical solution, compared with the prior art, the modified bimodal ABS special resin and the preparation method thereof provided by the present application have the following excellent effects:

[0020] 1) The present application discloses a modified bimodal ABS special resin for improving the compatibility of ABS resin in alloy, and introduces glycidyl methacrylate (GMA) to prepare a reactive modified butadiene-styrene-acrylonitrile graft copolymer, which forms an effective bonding graft on the interface between ABS resin and alloy resin, and improves the compatibility between alloy resins.

[0021] 2) The present application utilizes two kinds of latex M latex (PB latex with particle size of 320-335 nm) and T latex (PB latex with particle size of 280-290 nm) particles with different particle sizes for emulsion polymerization, and under the synergistic effect of the bimodal particles, the ABS resin has higher impact resistance while keeping the rigidity index unchanged. Therefore, the bimodal distribution ABS has more prominent comprehensive performance. It can ensure that when the ABS alloy resin is prepared, it has better adaptability with various alloy resins. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative labor on the basis of the provided drawings.

[0023] Figure 1 is a scanning electron microscope photograph of the impact section of the PBT / ABS alloy resin prepared in the comparative example and example 3, wherein a is the comparative example, and b is example 3. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present application will be described clearly and completely in combination with the embodiments of the present application and the drawings of the specification. Obviously, the described embodiments are only some of the embodiments of the present application, but 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 are within the protection scope of the present application.

[0025] The embodiment of the present application discloses a preparation method of modified bimodal ABS special resin.

[0026] In order to better understand the present application, the present application will be further specifically described by the following embodiments, but it should not be understood as a limitation of the present application. Some non-essential improvements and adjustments made by those skilled in the art based on the above content of the present application are also regarded as falling within the protection scope of the present application.

[0027] In the following, the technical solutions of the present application will be further described in combination with specific embodiments.

[0028] Example 1

[0029] The preparation method is suitable for modified bimodal ABS special resin.

[0030] In a 3L four-necked round flask, add 500g of water, 880g of M latex (PB latex with a particle size of 335nm), 240g of T latex (PB latex with a particle size of 290nm), 66g of ST (styrene), 32g of AN (acrylonitrile), adjust the pH value of the reaction to 11.2, and add a small amount of emulsifier, initiator, and molecular weight regulator TDDM, then add a reducing agent, sodium pyrophosphate, and ferrous sulfate solution as the reducing agent, and carry out the polymerization reaction at 60°C, and continuously heat to 70°C at a rate of 2°C / 10min for 30min.

[0031] Then, add a mixed solution of 210g of St, 95g of AN, and a small amount of initiator and molecular weight regulator at a constant rate for 2h. Then, increase the temperature to 75°C, add a small amount of a mixed solution of initiator, reducing agent, and reducing agent, and continue the reaction for 30min. Adjust the pH value to keep it constant, and then add 2.5g of GMA at a constant rate for 3min, and react for 40min. Finally, add a small amount of antioxidant, and age the reaction for 40min. The obtained emulsion is subjected to demulsification, washing, dehydration, and drying to obtain ABS modified powder.

[0032] The SAN resin has a melt index of 35.47g / 10min under the conditions of 220°C and 10kg, and a number average molecular weight of 62000.

[0033] After mixing 290g of modified grafting powder CHT, 700g of high-flow SAN resin, 0.5g of magnesium stearate, 7g of ethylene butyl acrylate, 2g of distearyl pentaerythritol diphosphite, and 0.5g of sulfurized dipropionate, extruding and granulating, and cutting into Φ3mm×Φ3mm cylindrical products after water cooling, a modified bimodal ABS special resin is obtained.

[0034] The temperature of the machine conveying section, plasticizing section, metering section, and die of the co-rotating twin-screw extruder is set to 200°C, 200°C, 220°C, and 230°C, respectively, and the machine is subjected to vacuum treatment with a vacuum degree of 0.05MPa.

[0035] Example 2

[0036] The modified bimodal ABS special resin is suitable for the preparation method:

[0037] In a 3L four-necked round flask, add 500g of water, 870g of M latex (PB latex with a particle size of 330nm), 230g of T latex (PB latex with a particle size of 285nm), 78g of ST (styrene), 24g of AN (acrylonitrile), adjust the pH value of the reaction to 10.6, and add a small amount of emulsifier, initiator, and molecular weight regulator TDDM, then add a reducing agent, sodium pyrophosphate, and ferrous sulfate solution as the reducing agent, and carry out the polymerization reaction at 60°C, and continuously heat to 70°C at a rate of 2°C / 10min for 30min.

[0038] Then, add a mixed solution of 200g of St, 85g of AN, and a small amount of initiator and molecular weight regulator at a constant rate for 2h, and then raise the temperature to 75°C, add a small amount of a mixed solution of initiator, reducing agent, and reducing agent, and continue the reaction for 30min. Adjust the pH value to keep constant, and then add 5g of GMA at a constant rate for 5min, and react for 40min. Finally, add a small amount of antioxidant, and mature the reaction for 40min. The obtained emulsion is subjected to demulsification, washing, dehydration, and drying to obtain ABS modified powder.

[0039] The SAN resin has a melt index of 34.61g / 10min under the conditions of 220°C and 10kg, and a number average molecular weight of 65000.

[0040] After mixing 300g of modified grafting powder CHT, 690g of SAN resin, 2g of magnesium stearate, 6.7g of ethylene butyl acrylate, 1g of distearyl pentaerythritol diphosphite, and 0.3g of sulfurized dipropionate, the mixture is extruded and granulated in a high-speed mixer for 5min, and then cooled in water and cut into Φ3mm×Φ3mm cylindrical products to obtain a modified bimodal ABS special resin;

[0041] The temperature of the machine conveying section, plasticizing section, metering section, and die of the co-rotating twin-screw extruder is set to 200°C, 210°C, 210°C, and 220°C, respectively, and the machine is subjected to vacuum treatment with a vacuum degree of 0.06MPa.

[0042] Experimental Example 3

[0043] The modified bimodal ABS special resin is prepared by the following method:

[0044] In a 3L four-necked round flask, add 500g of water, 870g of M latex (PB latex with a particle size of 320nm), 230g of T latex (PB latex with a particle size of 280nm), 70g of ST (styrene), 28g of AN (acrylonitrile), adjust the pH value of the reaction to 11.0, and add a small amount of emulsifier, initiator, and molecular weight regulator TDDM, then add a reducing agent, sodium pyrophosphate, and ferrous sulfate solution as a reducing agent, and carry out a polymerization reaction at 60°C, and continuously heat to 70°C at a rate of 2°C / 10min for 30min.

[0045] Then, add a mixed solution of 220g of St and 75g of AN, and a small amount of initiator and molecular weight regulator, at a constant rate for 2h, and then raise the temperature to 75°C, add a small amount of a mixed solution of initiator, reducing agent, and reducing agent, and continue the reaction for 30min. Adjust the pH value to keep it constant, and then add 10g of GMA at a constant rate for 10min, and react for 40min. Finally, add a small amount of antioxidant, and age the reaction for 40min. The obtained emulsion is subjected to demulsification, washing, dehydration, and drying to obtain ABS modified powder.

[0046] The SAN resin has a melt index of 34.53g / 10min under the conditions of 220°C and 10kg, and a number average molecular weight of 60000.

[0047] After mixing 240g of modified grafting powder CHT, 750g of SAN resin, 2g of magnesium stearate, 6g of ethylene butyl acrylate, 1.5g of distearyl pentaerythritol diphosphite, and 0.5g of sulfurized dipropionate, in a high-speed mixer for 5min, extrude and granulate, and cut into Φ3mm×Φ3mm cylindrical products after water cooling, to obtain a modified bimodal ABS special resin;

[0048] The temperature of the machine conveying section, plasticizing section, metering section, and die of the co-rotating twin-screw extruder is set to 210°C, 220°C, 230°C, and 240°C, respectively, and the machine is subjected to vacuum treatment with a vacuum degree of 0.05MPa.

[0049] Example 4

[0050] The modified bimodal ABS special resin is suitable for use in the preparation method:

[0051] In a 3L four-necked round flask, add 500g of water, 890g of M latex (PB latex with a particle size of 325nm), 220g of T latex (PB latex with a particle size of 280nm), 72g of ST (styrene), 27g of AN (acrylonitrile), adjust the pH value of the reaction to 11.4, and add a small amount of emulsifier, initiator and molecular weight regulator TDDM, then add a reducing agent, sodium pyrophosphate and ferrous sulfate solution as the reducing agent, and carry out the polymerization reaction at 60°C, and continuously heat to 70°C at a rate of 2°C / 10min for 30min.

[0052] Then add a mixed solution of 210g of St, 80g of AN, and a small amount of initiator and molecular weight regulator at a constant rate for 2h, and then raise the temperature to 75°C, add a small amount of mixed solution of initiator, reducing agent and reducing agent, and continue the reaction for 30min. Adjust the pH value to keep constant, and then add 12.5g of GMA at a constant rate for 13min, and the reaction time is 40min. Finally, add a small amount of antioxidant, and mature the reaction for 40min. The obtained emulsion is broken, washed, dehydrated and dried to obtain ABS modified powder.

[0053] The SAN resin has a melt index of 34.79g / 10min under the conditions of 220°C and 10kg, and a number average molecular weight of 61000.

[0054] After mixing 330g of modified grafting powder CHT, 660g of SAN resin, 3g of magnesium stearate, 3.5g of ethylene butyl acrylate, 3g of distearyl pentaerythritol diphosphite, and 0.5g of sulfurized dipropionic acid dioctadecyl ester in a high-speed mixer for 5min, extrude and granulate, and cut into Φ3mm×Φ3mm cylindrical products after water cooling to obtain modified bimodal ABS special resin;

[0055] The temperature of the machine conveying section, plasticizing section, metering section and die of the co-rotating twin-screw extruder is set to 210°C, 220°C, 240°C and 240°C respectively, and the machine is subjected to vacuum treatment at a vacuum degree of 0.07MPa.

[0056] Comparative Example

[0057] The modified bimodal ABS special resin is prepared by the following method:

[0058] In a 3L four-necked round flask, add 500g water, 870g M latex (PB latex with particle size of 320nm), 230g T latex (PB latex with particle size of 280nm), 70g ST (styrene), 28g AN (acrylonitrile), adjust the pH value of the reaction to 11.0, add a little emulsifier, initiator and molecular weight regulator TDDM, then add the reducing agent, sodium pyrophosphate and ferrous sulfate solution as reducing agent, and carry out the polymerization reaction at 60°C, and continuously heat up to 70°C at 2°C / 10min for 30min.

[0059] Then add a mixture solution of 220g St, 75g AN, a little initiator and molecular weight regulator into the four-necked flask at a constant speed for 2h. Then raise the temperature to 75°C, add a little mixture solution of initiator, reducing agent and reducing agent, and continue the reaction for 30min. Adjust the pH value to keep constant, and the reaction time is 40min. Finally, add a little antioxidant, and mature the reaction for 40min. The obtained emulsion is broken, washed, dehydrated and dried to obtain ABS modified powder.

[0060] The SAN resin has a melt index of 34.53g / 10min under the condition of 220°C and 10kg, and a number average molecular weight of 60000.

[0061] After mixing 240g grafted powder CHT, 750g SAN resin, 2g magnesium stearate, 6g ethylene butyl acrylate, 1.5g distearyl pentaerythritol diphosphite and 0.5g sulfurized dipropionate in a high-speed mixer for 5min, extrude and granulate, and cut into Φ3mm×Φ3mm cylindrical products after water cooling to obtain ABS resin.

[0062] The temperature of the conveying section, plasticizing section, metering section and die of the co-rotating twin-screw extruder is set to 210°C, 220°C, 230°C and 240°C respectively, and the extruder is subjected to vacuum treatment with a vacuum degree of 0.05MPa.

[0063] The performance indicators of the PBT / ABS alloy resin prepared by Examples 1-4 are as follows:

[0064] The above experimental data prove that this kind of modified bimodal ABS special resin is more suitable for the preparation of PBT / ABS alloy, and the obtained alloy has better impact resistance.

[0065] Further, the PBT / ABS alloy prepared by using the modified bimodal ABS special resin has better compatibility. The SEM photos of impact fracture section are enlarged 5000 times for comparison. The PBT / ABS alloy prepared by using the modified bimodal ABS special resin obtained in the experimental example 3 is shown in Fig. 1(b). It can be seen that the surface of the photo is more smooth than that of the comparative example 1(a), and there is no obvious delamination phenomenon.

[0066] The above description of disclosed embodiments enables one of ordinary skill in the art to make or use the application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing a modified bimodal ABS special resin, selected from bimodal ABS (butadiene-styrene-acrylonitrile terpolymer) latex and glycidyl methacrylate (GMA) graft polymerization, the bimodal ABS latex having two intervals of latex particle sizes, thus having better adaptability when used in various ABS alloys. The method is characterized in that, In a 3L four-necked round-bottom flask, 500g of water, 870-890g of M latex (PB latex with a particle size of 320-335nm), 220-240g of T latex (PB latex with a particle size of 280-290nm), 66-78g of ST (styrene), 24-32g of AN (acrylonitrile), and a small amount of emulsifier, initiator, and molecular weight regulator TDDM are added, and the pH value of the reaction is adjusted to be in the range of 10.6-11.

4. Then, a small amount of reducing agent, sodium pyrophosphate, and ferrous sulfate solution are added as reducing agents, and the polymerization reaction is carried out at 60°C. The temperature is continuously increased to 70°C at a rate of 2°C / 10min, and the duration is 30min. Then, a mixed solution of 200-220g of St, 75-95g of AN, and a small amount of initiator and molecular weight regulator is added at a constant rate for 2h. Then, the temperature is increased to 75°C, a small amount of mixed solution of initiator, reducing agent, and reducing agent is added, and the reaction is continued for 30min. The pH value is adjusted to be constant, and then 2.5-12.5g of GMA is added at a constant rate for 3-13min, and the reaction time is 40min. Finally, a small amount of antioxidant is added, and the reaction is aged for 40min. The obtained emulsion is subjected to demulsification, washing, dehydration, and drying to obtain ABS modified powder.

2. The process for preparing a modified bimodal ABS special resin according to claim 1, characterized in that, The M latex (PB latex with a particle size of 320-335nm) is 870-890g, the T latex (PB latex with a particle size of 280-290nm) is 220-240g, the ST (styrene) is 66-78g, the AN (acrylonitrile) is 24-32g, and the pH value of the reaction is adjusted to be in the range of 10.6-11.

4.

3. The method for preparing a modified bimodal ABS resin according to claim 1, characterized in that, In the increment reaction stage, 200-220g of St, 75-95g of AN, and 2.5-12.5g of GMA are added at a constant rate for 3-13min, and the reaction time is 40min.

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