A high-toughness, high-rigidity transparent ABS resin and its preparation method and application

Abstract

The present invention belongs to the field of synthetic resin technology, and specifically relates to a high-toughness, high-rigidity transparent ABS resin, its preparation method, and application. The present invention constructs a plastic core within the rubber particles during the preparation process, then performs graft polymerization on the surface of the rubber particles, and adjusts the refractive index of the core within the rubber particles to be consistent with that of the rubber phase, the graft layer phase, and the matrix resin phase to produce a highly transparent ABS resin. Because the rubber particles used to prepare the transparent ABS resin contain a highly rigid plastic core, silver streaks are more easily induced and induced during stress application, promoting hollowing within the rubber particles, thereby achieving a better balance of rigidity and toughness. In addition to having excellent light transmittance, the transparent ABS resin prepared by the present invention also has a tensile strength far exceeding that of similar commercially available products.

Description

Technical Field

[0001] The present invention belongs to the technical field of synthetic resins, and in particular relates to a high-toughness, high-rigidity transparent ABS resin and a preparation method and application thereof. Background Art

[0002] ABS resin (a terpolymer of acrylonitrile, butadiene and styrene) is widely used in automobile manufacturing, home appliances, electrical and electronic fields due to its good impact resistance, solvent resistance and easy processing properties. It has now become a cost-effective plastic.

[0003] ABS resin is essentially a modified polystyrene resin with an island-in-the-sea microstructure. In this island-in-the-sea structure, the dispersed phase is polybutadiene or a copolymer of butadiene and styrene, while the continuous phase is a copolymer of styrene and acrylonitrile. ABS resin is typically produced by two methods: bulk polymerization and emulsion blending. Of these two, emulsion blending is currently the most widely used, accounting for over 90% of total ABS resin production capacity.

[0004] Generally speaking, ABS resin is a white or slightly yellow solid particle and is not transparent. Transparent ABS resin is made by introducing methyl methacrylate into ABS resin to adjust the refractive index between the dispersed phase and the continuous phase, making them similar. This reduces the refraction and reflection of light within the resin, resulting in transparent ABS resin.

[0005] Transparent ABS resin generally boasts a light transmittance exceeding 88% and excellent impact resistance, making it suitable for applications in a wide range of fields, including refrigerators and new energy vehicles. In recent years, there have been numerous reports on transparent ABS resin. For example, patent CN 105008406 B describes a method for preparing a transparent ABS resin and a transparent ABS resin composition. The core technology utilizes a polybutadiene latex with a particle size of 310-320 nm as the rubber core layer. The rubber particles are then cross-linked to a gel content of 86-87%. This minimizes the penetration of styrene monomer into the rubber particles during the emulsion grafting process, preventing swelling of the polybutadiene rubber particles or internal grafting. Finally, a mixture of 27-36 wt% methyl methacrylate, 10-13 wt% styrene, and 2-6 wt% acrylonitrile is grafted onto the surface of a polybutadiene latex via emulsion graft polymerization to prepare a dispersed phase in a transparent ABS resin. The resulting transparent ABS latex is then coagulated and dried, then melt-blended with an MSAN resin prepared by bulk or suspension polymerization to produce a transparent ABS resin. The transparent ABS resin produced by this method exhibits high impact strength and a transmittance exceeding 90%. Patent CN 104136530 B reports a transparent ABS resin composition with excellent impact resistance, scratch resistance, and transparency. This preparation method also utilizes emulsion graft polymerization. Its core technology emphasizes the principle of maintaining transparency in transparent ABS resins. This requires ensuring that the absolute difference between the refractive index of the ABS graft copolymer and that of the polybutadiene rubber is less than 0.005, while also ensuring that the difference between the refractive index of the ABS graft copolymer and that of the matrix styrene and acrylonitrile copolymer is less than 0.005. Unlike patent CN 104136530B, this technology utilizes small-particle polybutadiene latex with a particle size of 75-150 nm. The resulting transparent ABS resin is melt-blended with a small amount of ABS graft copolymer and a styrene-acrylonitrile copolymer, resulting in a transparent ABS resin with excellent strength, high hardness, and low haze.

[0006] In addition, some bulk polymerization techniques are also used to produce transparent ABS resins. For example, CN 106699981 B and CN106221114B both use bulk polymerization to produce transparent ABS resins. This process uses styrene-butadiene rubber (SBR) or butadiene rubber (BBR) as the rubber phase. The rubber is then dissolved in a small amount of monomers containing a solvent, and then bulk polymerization is performed. The polymerization process controls the particle size of the rubber particles by controlling phase inversion during bulk polymerization, ultimately producing a transparent ABS resin with high impact strength and low residual monomer content.

[0007] Comparing the characteristics of the prior art, it can be seen that the impact strength of transparent ABS resin prepared by the bulk method is high, but the tensile strength is low, and the bulk method preparation process is relatively complex and requires high equipment. The impact strength of transparent ABS resin prepared by emulsion graft polymerization technology such as CN105008406B is high, but the strength is also low. The transparent ABS resin prepared by CN104136530 B technology has good strength and high hardness, but the impact strength is not satisfactory. Therefore, developing a transparent ABS resin with both high impact and high tensile strength is of great significance for meeting the market demand for high-end transparent ABS resin. Summary of the Invention

[0008] In view of the above problems and actual industrial development needs, the present invention proposes a high-toughness, high-rigidity transparent ABS resin and its preparation method and application.

[0009] It should be noted that the structure of the ABS graft copolymer used in the preparation of the transparent ABS resin of the present invention is different from the double-layer core-shell structure of traditional ABS resin, that is, polybutadiene or polystyrene-butadiene rubber is the core, and styrene, acrylonitrile and methacrylate are the shell.

[0010] The present invention adopts a binary or ternary copolymer of styrene, acrylonitrile and methyl methacrylate as the innermost core (this core is the plastic core), then constructs an outer core of polybutadiene or styrene-butadiene rubber on the surface of the plastic core (this layer is the rubber phase), and finally grafts a shell layer of a binary or ternary copolymer of styrene, acrylonitrile and methyl methacrylate on the surface of the outer core. The finally prepared ABS graft copolymer has a three-layer structure, that is, the innermost layer is the plastic core, the middle layer is the rubber layer, and the outermost layer is the graft layer.

[0011] In order to achieve the above object, the present invention adopts the following technical solutions:

[0012] The first technical purpose of the present invention is to provide a transparent ABS resin with high toughness and high rigidity, wherein the transparent ABS resin has a three-layer structure, namely, the innermost layer is a plastic core, the middle layer is a rubber layer, and the outermost layer is a graft layer;

[0013] The transparent ABS resin is a plastic core with a binary or ternary copolymer of styrene, acrylonitrile and methyl methacrylate as the innermost layer, an outer core of polybutadiene or styrene-butadiene rubber, i.e. a rubber layer, is constructed on the surface of the plastic core, and a shell layer, i.e. a grafted layer, of a binary or ternary copolymer of styrene, acrylonitrile and methyl methacrylate is grafted on the surface of the outer core of the rubber layer.

[0014] It is worth noting that by manipulating the refractive index of the three-layer polymer, an ABS graft copolymer is prepared. This is then melt-blended with an MSAN resin prepared by bulk or suspension polymerization, ultimately yielding a transparent ABS resin with excellent impact resistance and tensile strength. The core technology behind this process lies in the use of a plastic core as the innermost layer, which reinforces the resin. The inclusion of this plastic layer also creates a new rigidity-toughness balance within the ABS graft copolymer, strengthening the matrix resin while also enhancing its toughness through the rubber phase of the intermediate layer. This results in the production of a transparent ABS resin with both high toughness and rigidity.

[0015] The second technical purpose of the present invention is to provide a method for preparing the high-toughness, high-rigidity transparent ABS resin as described above.

[0016] A method for preparing a high-toughness, high-rigidity transparent ABS resin, comprising the following steps:

[0017] (1) The polymerization reactor is evacuated to a negative pressure, and after the air in the reactor is removed, 1-3 parts of an emulsifier, 0.1-2 parts of a pH regulator, and 60-100 parts of water are added. After the stirring device is turned on, 4-12 parts of a polymerization monomer A and 0.1-3 parts of a cross-linking agent A for preparing the innermost core are added; the temperature is then raised to 60-80° C., and after the temperature stabilizes, 0.1-1 parts of an initiator is added to initiate monomer polymerization; during the polymerization process, the reactor temperature is maintained at 60-85° C. for 1-3 hours to prepare the innermost plastic core.

[0018] (2) Continue to add 40-60 parts of polymerization monomer B into the reactor. The polymerization monomer B is added by continuous dropwise feeding. During the feeding process, the polymerization temperature of the reactor is maintained at 60-85°C, and the monomer dropwise addition time is controlled at 1-6 hours. After the monomer dropwise addition is completed, the temperature is raised to 80-95°C and kept warm for 2-3 hours to obtain a core layer latex with an innermost core layer of a plastic phase and an outer layer of a rubber phase.

[0019] (3) 50-70 parts (dry basis) of the prepared latex are placed in a reactor, 100-150 parts of deionized water are added, the temperature is raised to 40-70°C, 1-3 parts of an activator are added, 0.1-1 parts of an oxidant are added, and then 30-50 parts of a polymerization monomer C and 0.1-1 parts of an oxidant are continuously added over a period of 2-5 hours. After the addition is complete, the system is heated to 75-85°C and aged for 1-2 hours to complete the emulsion grafting reaction, thereby obtaining a transparent ABS graft copolymer latex.

[0020] (4) adding 1 part of an emulsion-type water-based antioxidant to 100 parts (dry basis) of the obtained ABS graft copolymer latex, mixing them thoroughly, and then injecting them into a 0.05-0.5% sulfuric acid or magnesium sulfate aqueous solution for flocculation and demulsification; the ratio of the ABS graft copolymer latex to the sulfuric acid flocculation solution is set to 1:1-2, the temperature during the flocculation process is set to 65-95°C, and the flocculation time is 10-40 minutes.

[0021] (5) After flocculation, the wet powder of the transparent ABS graft copolymer can be obtained by centrifugal separation, and the wet ABS graft copolymer powder can be dried to obtain the transparent ABS graft copolymer.

[0022] (6) Melt-extrude and blend 15-30 parts of the obtained transparent ABS graft copolymer powder with 70-85 parts of MSAN resin prepared by bulk polymerization or suspension polymerization to finally obtain transparent ABS resin.

[0023] Optionally, in step (1), the emulsifier is a mixture of one or more of potassium disproportionate rosin acid, potassium fatty acid, potassium oleate, sodium dodecyl sulfate, and sodium dodecylbenzene sulfonate; the pH regulator is a mixture of one or more of sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, and potassium dihydrogen phosphate; the polymerization monomer A is a mixture of one or more of styrene, acrylonitrile, methyl methacrylate, and α-methylstyrene; the cross-linking agent is a compound having two or more double bonds in its structure, such as a mixture of one or more of divinylbenzene, ethylene glycol dimethacrylate, allyl methacrylate, dicyclopentadiene acrylate, and triallyl isocyanurate; and the initiator is a free radical initiator, such as one of potassium persulfate, ammonium persulfate, and azoamidine hydrochloride.

[0024] Optionally, in step (2), the polymerization reaction monomer B is one or a mixture of butadiene, isoprene and styrene, preferably butadiene or a mixture of butadiene and styrene.

[0025] Optionally, in step (3), the activator refers to the reducing agent part of the redox initiator, which comprises an ionic reducing agent ferrous sulfate; an ionic chelating agent sodium pyrophosphate or EDTA sodium salt; a co-reducing agent Rongalite, etc.; the specific ratio of the configured activators is not strictly limited, and the preferred mass ratio is ferrous sulfate: EDTA: Rongalite = 0.005: 0.3: 0.5; the oxidizing agent is cumene hydroperoxide; the polymerization monomer C is a mixture of styrene, α-methylstyrene, acrylonitrile, and methyl methacrylate, and the ratios are mixed according to the refractive index matching principle, and the specific mass ratio is styrene (or α-methylstyrene): acrylonitrile: methyl methacrylate = 20-50: 50-80: 0-10, and preferably the mass ratio is styrene (or α-methylstyrene): acrylonitrile: methyl methacrylate = 24:70:6 or 41:53:6.

[0026] Optionally, in step (4), the composition of the emulsion-type aqueous antioxidant is a mixture of antioxidant 616 or antioxidant 1076 and antioxidant DLTP or DSTP, and the proportion of the mixture is not limited.

[0027] Optionally, in step (6), the MSAN resin is a resin prepared by bulk or suspension polymerization, wherein the difference in refractive index between the prepared transparent ABS graft copolymer and the resin is less than 0.005, and the specific proportions thereof are the same as those of the polymerized monomer C. Preferably, the refractive index of the prepared copolymer of styrene, acrylonitrile and methyl methacrylate is 1.515 or 1.534.

[0028] The third technical purpose of the present invention is to provide a transparent ABS resin with high toughness and high rigidity as described above for use in the fields of automobile manufacturing, household appliances, and electrical and electronic engineering.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] The present invention creates a highly transparent ABS resin by constructing a plastic core within the rubber particles during their preparation, then grafting the core onto the surface of the rubber particles. By aligning the refractive indices of the core, the rubber phase, the grafted layer phase, and the matrix resin phase, the resin is produced. Because the rubber particles used in this transparent ABS resin contain a highly rigid plastic core, silver streaks are more easily induced when the resin is subjected to stress, promoting the formation of cavitation within the rubber particles, thereby achieving a better balance of rigidity and toughness. In addition to excellent light transmittance, the transparent ABS resin produced by this invention also boasts a tensile strength far exceeding that of similar commercially available products. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0032] Figure 1 1 is the stress-strain curve of the transparent ABS resin prepared in Example 2 of the present invention. DETAILED DESCRIPTION

[0033] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0034] The term "embodiment" is used herein specifically to describe any embodiment as "exemplary," and should not be construed as superior or preferable to other embodiments. Performance indicators in the embodiments of this application were tested using conventional testing methods in the art, unless otherwise specified. It should be understood that the terms used in this application are intended solely to describe specific implementations and are not intended to limit the disclosure herein.

[0035] Unless otherwise specified, the technical and scientific terms used herein have the same meanings as commonly understood by ordinary technicians in the technical field to which this application belongs; other experimental methods and technical means not specifically specified in this application refer to experimental methods and technical means commonly used by ordinary technicians in this field.

[0036] In order to better illustrate the content of this application, numerous specific details are provided in the specific examples below. It should be understood by those skilled in the art that this application can be implemented without certain specific details. In the examples, some methods, means, instruments, equipment, etc. well known to those skilled in the art are not described in detail in order to highlight the main purpose of this application.

[0037] Under the premise of no conflict, the technical features disclosed in the embodiments of this application can be combined arbitrarily, and the resulting technical solutions belong to the contents disclosed in the embodiments of this application.

[0038] The invention discloses a high-toughness, high-rigidity transparent ABS resin and a preparation method thereof.

[0039] For a better understanding of the present invention, the present invention is further specifically described below through the following examples, but it should not be understood as limiting the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the above invention content are also considered to fall within the scope of protection of the present invention.

[0040] It should be noted that the experimental drugs used in the following examples are all analytically pure and there is no difference between products from different manufacturers.

[0041] Example 1

[0042] (1) The polymerization reactor was evacuated to a negative pressure, and after the air in the reactor was removed, 1 kg of emulsifiers of potassium soap of fatty acid and 2 kg of disproportionated potassium soap of rosin acid, 0.5 kg of pH regulator of sodium carbonate and 60 kg of water were added. After the stirring device was turned on, 4 kg of polymerization monomers A (3 kg of methyl methacrylate and 1 kg of styrene) and 0.1 kg of cross-linking agent of divinylbenzene for preparing the innermost core were added. The temperature was then raised to 65°C. After the temperature stabilized, 1 kg of initiator of potassium persulfate was added to initiate the polymerization of the monomers. During the polymerization process, the reactor temperature was maintained at 65°C for 1 hour to prepare the innermost plastic core.

[0043] (2) 56 kg of polymerization monomer B butadiene was continuously added to the reactor. The polymerization temperature of the reactor was maintained at 65°C during the feeding process, and the monomer addition time was controlled at 4 hours. After the monomer addition was completed, the temperature was raised to 85°C and kept warm for 2 hours to obtain a core latex with the innermost core being a plastic phase and the outer layer being a rubber phase.

[0044] (3) 60 kg (dry basis) of the latex prepared above was placed in a reactor, 150 kg of deionized water was added, and the temperature was raised to 60°C. 1 kg of an activator (the activator was a mixture of ferrous sulfate, EDTA, and Rongalite in a mass ratio of 0.005:0.3:0.5) was added, and 0.1 kg of an oxidant, cumene hydroperoxide, was added. Then, 40 kg of polymerization monomer C (wherein the mass ratio of styrene:methyl methacrylate:acrylonitrile was 24:70:6) and 0.4 kg of an oxidant, cumene hydroperoxide, were continuously added, and the addition time was 2 hours. After the addition was completed, the system was heated to 75°C for aging for 1 hour to complete the emulsion grafting reaction, and a transparent ABS graft copolymer latex was obtained.

[0045] (4) 100 kg (dry basis) of the obtained ABS graft copolymer latex was added with 1 part of an emulsion-type water-based antioxidant (the effective composition of the antioxidant was antioxidant 1076 and DLTP, with a mass ratio of 2:1) and after thorough mixing, the mixture was injected into a 0.05% sulfuric acid aqueous solution for flocculation and demulsification; the ratio of the ABS graft copolymer latex to the sulfuric acid flocculant was set to 1:2, the temperature during the flocculation process was set at 65°C, and the flocculation time was 40 min.

[0046] (5) After flocculation, the wet powder of the transparent ABS graft copolymer can be obtained by centrifugal separation, and the wet ABS graft copolymer powder can be dried to obtain the transparent ABS graft copolymer.

[0047] (6) 25 kg of the transparent ABS graft copolymer powder obtained above was melt-extruded and blended with 75 kg of MSAN resin (refractive index 1.515, whose specific composition is the same as that of the polymerized monomer C, i.e., styrene:methyl methacrylate:acrylonitrile in a mass ratio of 24:70:6) prepared by bulk polymerization or suspension polymerization to obtain a transparent ABS resin.

[0048] Example 2

[0049] (1) The polymerization reactor was evacuated to a negative pressure, and after the air in the reactor was removed, 1 kg of potassium oleate and 1 kg of disproportionated rosin acid potassium soap and 0.5 kg of sodium lauryl sulfate as emulsifiers, 0.5 kg of sodium carbonate and 0.5 kg of sodium bicarbonate as pH regulators, and 60 kg of water were added. After the stirring device was turned on, 8 kg of polymerization monomers A (6 kg of methyl methacrylate and 2 kg of styrene) for preparing the innermost core and 0.2 kg of ethylene glycol dimethacrylate as a crosslinker were added. The temperature was then raised to 65° C., and after the temperature stabilized, 0.7 kg of ammonium persulfate as an initiator was added to initiate monomer polymerization. During the polymerization process, the reactor temperature was maintained at 70° C. for 1 hour to prepare the innermost plastic core.

[0050] (2) 52 kg of polymerization monomer B butadiene was continuously added to the reactor. The polymerization temperature of the reactor was maintained at 70°C during the feeding process, and the monomer addition time was controlled at 3 hours. After the monomer addition was completed, the temperature was raised to 85°C and the temperature was kept at this temperature for 2 hours to obtain a core latex with the innermost core being a plastic phase and the outer layer being a rubber phase.

[0051] (3) 60 kg (dry basis) of the prepared latex was placed in a reactor, 150 kg of deionized water was added, and the temperature was raised to 65°C. 1 kg of activator (the specific ratio of activator was ferrous sulfate: EDTA: Rongalite = 0.005:0.3:0.5) was added, followed by 0.1 kg of cumene hydroperoxide as an oxidant. Then, 40 kg of polymerization monomer C (wherein the mass ratio of styrene: methyl methacrylate: acrylonitrile was 24:70:6) and 0.4 kg of cumene hydroperoxide as an oxidant were continuously added over a 2-hour dropwise addition period. After the dropwise addition was completed, the system was heated to 85°C and aged for 1 hour to complete the emulsion grafting reaction, thereby obtaining a transparent ABS graft copolymer latex.

[0052] (4) 1 kg of an emulsion-type water-based antioxidant (the effective composition of the antioxidant is antioxidant 1076 and DSTP, with a mass ratio of 2:1) was added to 100 kg (dry basis) of the obtained ABS graft copolymer latex. After thorough mixing, the mixture was injected into a 0.2% magnesium sulfate solution for flocculation and demulsification. The ratio of the ABS graft copolymer latex to the sulfuric acid flocculant was set to 1:2. The temperature during the flocculation process was set at 75°C, and the flocculation time was 30 min.

[0053] (5) After flocculation, the wet powder of the transparent ABS graft copolymer can be obtained by centrifugal separation, and the wet ABS graft copolymer powder can be dried to obtain the transparent ABS graft copolymer.

[0054] (6) 25 kg of the transparent ABS graft copolymer powder obtained above was melt-extruded and blended with 75 kg of MSAN resin (refractive index 1.515, and its specific composition is the same as that of the polymerized monomer C, i.e., styrene: methyl methacrylate: acrylonitrile in a mass ratio of 24:70:6) prepared by bulk polymerization or suspension polymerization to obtain a transparent ABS resin.

[0055] Example 3

[0056] (1) After the polymerization reactor was evacuated to remove air from the reactor, 1 kg of potassium oleate and 1 kg of disproportionated rosin acid potassium soap and 0.5 kg of sodium dodecylbenzene sulfonate as emulsifiers, 0.5 kg of potassium dihydrogen phosphate and 0.5 kg of sodium bicarbonate as pH adjusters, and 60 kg of water were added. After the stirring device was turned on, 12 kg of polymerization monomer A (9 kg of methyl methacrylate and 3 kg of styrene) for preparing the innermost core and 0.2 kg of ethylene glycol dimethacrylate as crosslinker were added. The temperature was then raised to 65°C. After the temperature stabilized, 0.7 kg of ammonium persulfate as initiator was added to initiate monomer polymerization. During the polymerization process, the reactor temperature was maintained at 70°C for 1 hour. This was to prepare the innermost plastic core.

[0057] (2) 48 kg of the polymerization monomer B, isoprene, was continuously added to the reactor. The polymerization temperature of the reactor was maintained at 70°C during the addition process, and the monomer addition time was controlled within 1 hour. After the monomer addition was completed, the temperature was raised to 85°C and the temperature was maintained for 2 hours to obtain a core latex having an innermost core of a plastic phase and an outer layer of a rubber phase.

[0058] (3) 60 kg (dry basis) of the latex prepared above was placed in a reactor, 150 kg of deionized water was added, and the temperature was raised to 55° C., 1 kg of an activator (the specific ratio of the activator was ferrous sulfate: EDTA: Rongalite = 0.005:0.3:0.5) was added, and 0.2 kg of an oxidant, cumene hydroperoxide, was added. Then, 40 kg of polymerization monomer C (wherein the mass ratio of styrene: methyl methacrylate: acrylonitrile was 25:75:0) and 0.5 kg of an oxidant, cumene hydroperoxide, were continuously added, and the addition time was 2 hours. After the addition was completed, the system was heated to 75° C. and aged for 1 hour to complete the emulsion grafting reaction, thereby obtaining a transparent ABS graft copolymer latex.

[0059] (4) 1 kg of an emulsion-type water-based antioxidant (the effective composition of the antioxidant is antioxidant 616 and DSTP, with a mass ratio of 6:4) was added to 100 kg (dry basis) of the obtained ABS graft copolymer latex. After thorough mixing, the mixture was injected into a 0.2% magnesium sulfate solution for flocculation and demulsification. The ratio of the ABS graft copolymer latex to the sulfuric acid flocculant was set to 1:2. The temperature during the flocculation process was set at 75°C, and the flocculation time was 30 min.

[0060] (5) After flocculation, the wet powder of the transparent ABS graft copolymer can be obtained by centrifugal separation, and the wet ABS graft copolymer powder can be dried to obtain the transparent ABS graft copolymer.

[0061] (6) 25 kg of the transparent ABS graft copolymer powder obtained above was melt-extruded and blended with 75 kg of MSAN resin (refractive index 1.515, copolymer composition styrene: methyl methacrylate: acrylonitrile mass ratio of 24:70:6) prepared by bulk polymerization or suspension polymerization to obtain transparent ABS resin.

[0062] Example 4

[0063] (1) After the polymerization reactor was evacuated to a negative pressure and the air in the reactor was removed, 1 kg of potassium oleate and 1 kg of disproportionated rosin acid potassium soap and 0.5 kg of sodium dodecylbenzene sulfonate as emulsifiers, 0.5 kg of potassium dihydrogen phosphate and 0.5 kg of sodium bicarbonate as pH adjusters, and 100 kg of water were added. After the stirring device was turned on, 12 kg of polymerization monomer A (9 kg of methyl methacrylate and 3 kg of styrene) for preparing the innermost core and 0.1 kg of allyl methacrylate as crosslinker were added. The temperature was then raised to 65°C. After the temperature stabilized, 0.7 kg of ammonium persulfate as initiator was added to initiate monomer polymerization. During the polymerization process, the reactor temperature was maintained at 70°C for 1 hour. This was to prepare the innermost plastic core.

[0064] (2) 48 kg of polymerization monomer B butadiene was continuously added to the reactor. The polymerization temperature of the reactor was maintained at 70°C during the feeding process, and the monomer addition time was controlled to be 1 hour. After the monomer addition was completed, the temperature was raised to 85°C and kept warm for 2 hours to obtain a core latex with the innermost core being a plastic phase and the outer layer being a rubber phase.

[0065] (3) 60 kg (dry basis) of the latex prepared above was placed in a reactor, 150 kg of deionized water was added, and the temperature was raised to 55° C., 1 kg of an activator (the specific ratio of the activator was ferrous sulfate: EDTA: Rongalite = 0.005:0.3:0.5) was added, and 0.2 kg of an oxidant, cumene hydroperoxide, was added, and then polymerization monomer C (wherein the mass ratio of styrene: methyl methacrylate: acrylonitrile was 24:70:6) and 0.5 kg of an oxidant, cumene hydroperoxide, were continuously added, and the addition time was 2 hours. After the addition was completed, the system was heated to 75° C. and aged for 1 hour to complete the emulsion grafting reaction, thereby obtaining a transparent ABS graft copolymer latex.

[0066] (4) 1 kg of an emulsion-type water-based antioxidant (the effective composition of the antioxidant is antioxidant 616 and DLTP, with a mass ratio of 6:4) was added to 100 kg (dry basis) of the obtained ABS graft copolymer latex. After thorough mixing, the mixture was injected into a 0.2% magnesium sulfate solution for flocculation and demulsification. The ratio of the ABS graft copolymer latex to the sulfuric acid flocculant was set to 1:2. The temperature during the flocculation process was set at 75°C, and the flocculation time was 30 min.

[0067] (5) After flocculation, the wet powder of the transparent ABS graft copolymer can be obtained by centrifugal separation, and the wet ABS graft copolymer powder can be dried to obtain the transparent ABS graft copolymer.

[0068] (6) 25 kg of the transparent ABS graft copolymer powder obtained above was melt-extruded and blended with 75 kg of MSAN resin (refractive index 1.515, copolymer composition styrene: methyl methacrylate: acrylonitrile mass ratio of 24:70:6) prepared by bulk polymerization or suspension polymerization to obtain transparent ABS resin.

[0069] Example 5

[0070] (1) The polymerization reactor was evacuated to a negative pressure, and after the air in the reactor was removed, 1 kg of potassium oleate and 1 kg of disproportionated rosin acid potassium soap and 0.5 kg of sodium dodecylbenzene sulfonate as emulsifiers, 0.5 kg of potassium dihydrogen phosphate and 0.5 kg of sodium bicarbonate as pH regulators, and 100 kg of water were added. After the stirring device was turned on, 4 kg of polymerization monomers A (2.3 kg of methyl methacrylate and 1.7 kg of styrene) for preparing the innermost core and 0.1 kg of allyl methacrylate as crosslinking agent were added. The temperature was then raised to 65° C., and after the temperature stabilized, 0.7 kg of ammonium persulfate as initiator was added to initiate monomer polymerization. During the polymerization process, the reactor temperature was maintained at 70° C. for 1 hour to prepare the innermost plastic core.

[0071] (2) 42 kg of polymerization monomer B butadiene and 14 kg of styrene were continuously added to the reactor. The polymerization temperature of the reactor was maintained at 70°C during the feeding process, and the monomer addition time was controlled at 6 hours. After the monomer addition was completed, the temperature was raised to 85°C and the temperature was maintained for 2 hours to obtain a core latex with the innermost core being a plastic phase and the outer layer being a rubber phase.

[0072] (3) 60 kg (dry basis) of the latex prepared above was placed in a reactor, 150 kg of deionized water was added, and the temperature was raised to 55° C., 1 kg of an activator (the specific ratio of the activator was ferrous sulfate: EDTA: Rongalite = 0.005:0.3:0.5) was added, and 0.2 kg of an oxidant, cumene hydroperoxide, was added. Then, 40 kg of polymerization monomer C (wherein the mass ratio of styrene: methyl methacrylate: acrylonitrile was 41:53:6) and 0.5 kg of an oxidant, cumene hydroperoxide, were continuously added, and the addition time was 2 hours. After the addition was completed, the system was heated to 75° C. and aged for 1 hour to complete the emulsion grafting reaction, thereby obtaining a transparent ABS graft copolymer latex.

[0073] (4) 1 kg of an emulsion-type water-based antioxidant (the effective composition of the antioxidant is antioxidant 616 and DLTP, with a mass ratio of 6:4) was added to 100 kg (dry basis) of the obtained ABS graft copolymer latex. After thorough mixing, the mixture was injected into a 0.5% magnesium sulfate solution for flocculation and demulsification. The ratio of the ABS graft copolymer latex to the sulfuric acid flocculant was set to 1:2. The temperature during the flocculation process was set at 85°C, and the flocculation time was 20 min.

[0074] (5) After flocculation, the wet powder of the transparent ABS graft copolymer can be obtained by centrifugal separation, and the wet ABS graft copolymer powder can be dried to obtain the transparent ABS graft copolymer.

[0075] (6) 25 kg of the transparent ABS graft copolymer powder obtained above was melt-extruded and blended with 75 kg of MSAN resin (refractive index 1.534, copolymer composition styrene: methyl methacrylate: acrylonitrile mass ratio of 41:53:6) prepared by bulk polymerization or suspension polymerization to obtain transparent ABS resin.

[0076] Example 6

[0077] (1) The polymerization reactor was evacuated to a negative pressure, and after the air in the reactor was removed, 1 kg of potassium oleate, 1 kg of disproportionated rosin acid potassium soap, 0.5 kg of sodium dodecylbenzene sulfonate, 0.5 kg of potassium dihydrogen phosphate, 0.5 kg of sodium bicarbonate, and 100 kg of water were added. After the stirring device was turned on, 8 kg of polymerization monomers A (5 kg of methyl methacrylate, 2 kg of styrene, and 1 kg of acrylonitrile) for preparing the innermost core and 0.1 kg of allyl methacrylate as a crosslinking agent were added. The temperature was then raised to 65° C., and after the temperature stabilized, 0.7 kg of ammonium persulfate as an initiator was added to initiate monomer polymerization. During the polymerization process, the reactor temperature was maintained at 70° C. for 1 hour to prepare the innermost plastic core.

[0078] (2) Continue to add 48 kg of polymerization monomer B butadiene and 4 kg of styrene into the reactor. The polymerization monomer B butadiene and styrene are added by continuous dropwise feeding. During the feeding process, the polymerization temperature of the reactor is maintained at 70 ° C. The monomer dropwise addition time is controlled within 4 hours. After the monomer dropwise addition is completed, the temperature is raised to 85 ° C. After the temperature is maintained for 2 hours, a core layer latex is obtained in which the innermost core layer is a plastic phase and the outer layer is a rubber phase.

[0079] (3) 60 kg (dry basis) of the latex prepared above was placed in a reactor, 150 kg of deionized water was added, and the temperature was raised to 55° C., 1 kg of an activator (the specific ratio of the activator was ferrous sulfate: EDTA: Rongalite = 0.005:0.3:0.5) was added, 0.2 kg of an oxidant, cumene hydroperoxide, was added, and then polymerization monomer C (wherein the mass ratio of styrene, methyl methacrylate and acrylonitrile was 27:68:5) and 0.5 kg of an oxidant, cumene hydroperoxide, were continuously added, and the addition time was 2 hours. After the addition was completed, the system was heated to 75° C. and aged for 1 hour to complete the emulsion grafting reaction, thereby obtaining a transparent ABS graft copolymer latex.

[0080] (4) 100 kg (dry basis) of the obtained ABS graft copolymer latex was added with 1 kg of an emulsion-type water-based antioxidant (the antioxidant's effective composition was antioxidant 616 and DLTP, with a mass ratio of 6:4). After thorough mixing, the mixture was poured into a 0.5% magnesium sulfate solution for flocculation and demulsification. The ratio of ABS graft copolymer latex to sulfuric acid flocculant was set at 1:2. The temperature during the flocculation process was set at 85°C, and the flocculation time was 10 minutes.

[0081] (5) After flocculation, the wet powder of the transparent ABS graft copolymer can be obtained by centrifugal separation, and the wet ABS graft copolymer powder can be dried to obtain the transparent ABS graft copolymer.

[0082] (6) 25 kg of the above-mentioned transparent ABS graft copolymer powder was melt-extruded and blended with 75 kg of MSAN resin (refractive index 1.52, the copolymer composition of which is the same as the composition of monomer C, specifically the mass ratio of styrene: methyl methacrylate: acrylonitrile is 27:68:5) prepared by bulk polymerization or suspension polymerization to obtain transparent ABS resin.

[0083] In order to further demonstrate the beneficial effects of the present invention and to better understand the present invention, the following comparative examples are provided to further illustrate the technical features disclosed in the present invention, but they should not be construed as limiting the present invention. Other improvements made by those skilled in the art based on the above invention without inventive work are also considered to fall within the scope of protection of the present invention.

[0084] The transparent ABS resin obtained above was prepared into standard impact, tensile, and light transmission test strips based on ASTM D256 (2010), ASTM D 638 (2014), and ISO 13468-2 (1999). The test results are shown in the table below. For comparison, transparent ABS resin TR-558 from LG Electronics (South Korea) and transparent ABS PA-758 from Chi Mei (Taiwan) were used as Comparative Examples 1 and 2, respectively. The specific results are shown in the table below:

[0085]

[0086]

[0087] Analysis of the test results reveals that the light transmittance and haze values ​​of the transparent ABS resin prepared in the present invention are comparable to those of commercially available products, with the light transmittance exceeding that of commercially available products. The impact strength and tensile strength of Examples 1, 2, and 5, as well as the mechanical properties of the transparent ABS resin prepared in the present invention, are all higher than those of commercially available products, demonstrating a superior balance of rigidity and toughness.

[0088] It is noteworthy that by constructing a plastic core within the rubber particles, the rigidity of the resulting transparent ABS resin can be increased without affecting transparency. The efficiency of the rigidity enhancement varies depending on the proportion of the plastic core in the core layer. Isoprene can replace butadiene in the preparation of transparent ABS resin, but because its glass transition temperature is higher than that of polybutadiene, its toughening efficiency is inferior to that of butadiene. When styrene partially replaces butadiene as the rubber phase in transparent ABS, the light transmission properties of the resulting transparent ABS resin are essentially unaffected, but its impact strength is somewhat reduced.

[0089] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A high toughness, high rigidity transparent ABS resin, characterized in that: By adjusting the refractive index of the three-layer polymer, an ABS graft copolymer was prepared and melt-blended with MSAN resin prepared by bulk polymerization or suspension polymerization to finally prepare a transparent ABS resin with good impact properties and tensile strength. The ABS graft copolymer has a three-layer structure, that is, the innermost layer is a plastic core, the middle layer is a rubber layer, and the outermost layer is a graft layer; The ABS graft copolymer is a plastic core with a styrene and methyl methacrylate binary copolymer or a styrene, acrylonitrile and methyl methacrylate ternary copolymer as the innermost layer, an outer core of polybutadiene or styrene butadiene rubber, i.e., a rubber layer, is constructed on the surface of the plastic core, and a shell layer, i.e., a graft layer, of a ternary copolymer of styrene, acrylonitrile and methyl methacrylate is grafted onto the surface of the outer core of the rubber layer.

2. A method for preparing the high-toughness, high-rigidity transparent ABS resin according to claim 1, characterized in that: The specific steps are as follows: (1) After the reactor is emptied, 1-3 parts of emulsifier, 0.1-2 parts of pH regulator and 60-100 parts of water are added, and while stirring, 4-12 parts of polymerization monomer A and 0.1-3 parts of cross-linking agent A for preparing the innermost core are added; then the temperature is raised, and after the temperature stabilizes, 0.1-1 parts of initiator is added to initiate monomer polymerization to prepare the innermost plastic core; (2) continuously adding 40-60 parts of the polymerization reaction monomer B to the reactor in step (1), and heating the reaction after the monomer addition is completed to obtain a core layer latex with the innermost core being a plastic phase and the outer layer being a rubber phase; (3) 50-70 parts of the core layer latex prepared in step (2) on a dry basis are placed in a reactor, 100-150 parts of deionized water are added, the temperature is raised, and 1-3 parts of an activator and 0.1-1 parts of an oxidant are added; then 30-50 parts of a polymerization monomer C and 0.1-1 parts of an oxidant are continuously added dropwise; after the addition is complete, the system is heated and matured to complete the emulsion grafting reaction, thereby obtaining a transparent ABS graft copolymer latex; (4) Add 1 part of an emulsion-type water-based antioxidant to 100 parts of the ABS graft copolymer latex obtained in step (3) on a dry basis, mix thoroughly, and inject into a 0.05-0.5% concentration of sulfuric acid or magnesium sulfate aqueous solution for flocculation and demulsification; centrifuge and dry to obtain a transparent ABS graft copolymer; (5) 15-30 parts of the transparent ABS graft copolymer powder obtained in step (4) and 70-85 parts of the MSAN resin prepared by bulk polymerization or suspension polymerization are melt-extruded and blended to finally obtain the high-toughness, high-rigidity transparent ABS resin.

3. The method for preparing a high-toughness, high-rigidity transparent ABS resin according to claim 2, characterized in that: In step (1), the emulsifier is one or a mixture of potassium disproportionate rosin acid, potassium fatty acid, potassium oleate, sodium dodecyl sulfate, and sodium dodecylbenzene sulfonate; the pH adjuster is one or a mixture of sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, and potassium dihydrogen phosphate; the cross-linking agent A is a compound containing two or more double bonds in its structure; and the initiator is a free radical initiator.

4. The method for preparing a high-toughness, high-rigidity transparent ABS resin according to claim 3, characterized in that: The crosslinking agent A is one of divinylbenzene, ethylene glycol dimethacrylate, allyl methacrylate, dicyclopentadiene acrylate, triallyl isocyanurate, or a mixture thereof; the initiator is one of potassium persulfate, ammonium persulfate, and azoamidine hydrochloride.

5. The method for preparing a high-toughness, high-rigidity transparent ABS resin according to claim 2 or 3, characterized in that: In the step (1), the temperature for adding the initiator is 60-80°C, the polymerization reaction temperature is 60-85°C, and the reaction time is 1-3 hours.

6. The method for preparing a high-toughness, high-rigidity transparent ABS resin according to claim 2, characterized in that: In step (2), the monomer addition time is 1-6 h. After the addition is completed, the temperature of the reactor is raised to 80-95°C, and the reaction time is 2-3 h.

7. The method for preparing a transparent ABS resin with high toughness and high rigidity according to claim 2, characterized in that: In step (3), the activator refers to the reducing agent part in the redox initiator, and its composition includes ionic reducing agent ferrous sulfate; ionic chelating agent sodium pyrophosphate or EDTA sodium salt; auxiliary reducing agent Rongalite; the specific ratio of the configured activator is not strictly limited, and its mass ratio is ferrous sulfate: EDTA: Rongalite = 0.005: 0.3: 0.5; the oxidant is isopropyl benzene hydroperoxide; the polymerization reaction monomer C is styrene, acrylonitrile and methyl methacrylate mixed according to the refractive index matching principle, and the specific mixing ratio is styrene: acrylonitrile: methyl methacrylate = 20~50: 50~80: 0~10.

8. The method for preparing a transparent ABS resin with high toughness and high rigidity according to claim 7, characterized in that: The mixing ratio of styrene, acrylonitrile and methyl methacrylate is styrene: acrylonitrile: methyl methacrylate = 24:70:6 or 41:53:

6.

9. The method for preparing a high-toughness, high-rigidity transparent ABS resin according to claim 2 or 7, characterized in that: In step (3), the temperature for adding the activator and the oxidant is 40-70°C, and the addition time is 2-5 hours; the reaction temperature is 75-85°C, and the reaction time is 1-2 hours.

10. The method for preparing a transparent ABS resin with high toughness and high rigidity according to claim 2, characterized in that: The emulsion-type water-based antioxidant is composed of a mixture of antioxidant 616 or antioxidant 1076 and antioxidant DLTP or DSTP; the MSAN resin is a resin prepared by bulk or suspension polymerization, which is a polymer of styrene, acrylonitrile and methyl methacrylate and has a refractive index that differs from the refractive index of the transparent ABS graft copolymer prepared above by less than 0.005; The ratio of the ABS graft copolymer latex to the sulfuric acid flocculation liquid is 1:1-2, the flocculation temperature is 65-95° C., and the flocculation time is 10-40 minutes.

11. Use of the high-toughness, high-rigidity transparent ABS resin according to claim 1 or the high-toughness, high-rigidity transparent ABS resin prepared by the method according to claim 2 in the fields of automobile manufacturing, household appliances, and electrical and electronic engineering.

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