High-toughness and high-rigidity transparent ABS (Acrylonitrile Butadiene Styrene) resin as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of synthetic resin, and particularly relates to high-toughness and high-rigidity transparent ABS (Acrylonitrile Butadiene Styrene) resin as well as a preparation method and application thereof. Plastic cores are constructed in rubber particles in the process of preparing the rubber particles, then graft polymerization is performed on the surfaces of the rubber particles, and the high-transparency ABS resin is prepared by regulating and controlling the refractive indexes of the inner cores of the rubber particles to be consistent with those of a rubber phase, a graft layer phase and a matrix resin phase. The rubber particles used for preparing the transparent ABS resin internally comprise the plastic cores with relatively high rigidity, so that crazing can be more easily initiated and induced in a resin stress process, internal cavitation of the rubber particles is promoted, and rigid-tough balance can be better constructed. The transparent ABS resin prepared by the invention has excellent light transmission, and the tensile strength of the transparent ABS resin is far away from that of similar products sold in supermarkets.

Description

Technical Field

[0001] The 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 (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 polystyrene modified resin, and its microstructure presents an island structure. In the island structure, the dispersed phase is polybutadiene or a copolymer of butadiene and styrene, and the continuous phase is a copolymer of styrene and acrylonitrile. Generally, the preparation methods of ABS resin include bulk polymerization technology and emulsion blending technology. Of these two technologies, emulsion blending technology is currently the most widely used, accounting for more than 90% of the total production capacity of ABS resin.

[0004] Generally speaking, ABS resin is in the form of white or slightly yellow solid particles 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 their refractive index similar, thereby reducing the refraction and reflection of light inside the resin, making the ABS resin transparent.

[0005] The light transmittance of transparent ABS resin can generally reach more than 88%, and it has excellent impact resistance. It can be used in many fields such as refrigerators and new energy vehicles. In recent years, there have been many reports on transparent ABS resin. For example, patent CN 105008406 B reports a method for preparing a transparent ABS resin and a transparent ABS resin composition. The core technology is to use a polybutadiene latex with a particle size of 310-320nm as the rubber core layer, and then crosslink the rubber particles to a gel content of 86-87% to ensure that the degree of infiltration of styrene monomer into the rubber particles is minimized during the emulsion grafting process, so as to avoid swelling of the polybutadiene rubber particles or internal grafting by styrene monomer. Finally, 27-36wt% of methyl methacrylate, 10-13wt% of styrene and 2-6wt% of acrylonitrile are mixed and grafted onto the surface of polybutadiene latex by emulsion graft polymerization to prepare the dispersed phase in the transparent ABS resin, and then the obtained transparent ABS latex is melt-blended with the MSAN resin prepared by bulk or suspension polymerization after flocculation and drying, so as to prepare the transparent ABS resin. The transparent ABS resin prepared by this method has high impact strength and the transmittance can reach more than 90%. Patent CN 104136530 B reports a transparent ABS resin composition with excellent impact resistance, scratch resistance and transparency. The preparation method also adopts emulsion graft polymerization technology. The core technology is that it emphasizes the principle of transparent ABS resin to maintain transparency in principle, that is, it is necessary to ensure that the absolute value of the difference between the refractive index of the ABS graft copolymer and the refractive index of the polybutadiene rubber is less than 0.005, and it is also necessary to ensure that the difference between the refractive index of the ABS graft copolymer and the matrix styrene and acrylonitrile copolymer matrix resin is also less than 0.005. Different from the patent CN 104136530B, the particle size of the polybutadiene rubber used in this technology is between 75-150nm, which is a small-particle polybutadiene latex. A small amount of ABS graft copolymer is melt-blended with styrene and acrylonitrile-based copolymer in the prepared transparent ABS resin to prepare a transparent ABS resin with good strength, high hardness and low haze value.

[0006] In addition, some bulk polymerization techniques are also used to prepare transparent ABS resins, such as CN 106699981 B and CN106221114B, which use bulk polymerization technology to prepare transparent ABS resins. In this preparation process, styrene-butadiene rubber or butadiene rubber is used as the rubber phase, and then the rubber is dissolved in a monomer with a small amount of solvent, and then bulk polymerization is performed. The polymerization process controls the particle size of the rubber particles by controlling the phase inversion in the bulk polymerization, and finally prepares a transparent ABS resin with high impact strength and less residual monomers.

[0007] By comparing the characteristics of the prior art, it can be seen that the impact strength of the transparent ABS resin prepared by the bulk method is high, but the tensile strength is low, and the bulk method preparation process is relatively complicated and has high requirements on equipment. The transparent ABS resin prepared by emulsion graft polymerization technology such as CN105008406B has high impact strength, but the strength is also low. The transparent ABS resin prepared by CN 104136530 B technology has good strength and high hardness, but the impact strength is not satisfactory. Therefore, it is of great significance to develop a transparent ABS resin with both high impact and high tensile strength to meet 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 provides a high-toughness, high-rigidity transparent ABS resin and a preparation method and application thereof.

[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 the 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 a plastic core), then constructs an outer core of polybutadiene or styrene-butadiene rubber on the surface of the plastic core (this layer is a 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 ABS graft copolymer finally prepared 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.

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

[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 grafted 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 the ABS graft copolymer is prepared by adjusting the refractive index of the three-layer polymer, and melt-blended with the MSAN resin prepared by bulk polymerization or suspension polymerization, and finally a transparent ABS resin with good impact performance and tensile strength is prepared. Its core technology is that the plastic core used is the innermost layer, which serves the purpose of strengthening the resin. The use of the plastic layer also enables the ABS graft copolymer to construct a new rigid-tough balance system, which strengthens the matrix resin while also using the rubber phase of the middle layer to toughen it, achieving the purpose of preparing a transparent ABS resin with high toughness and high 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, the specific steps are as follows:

[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 adjuster, and 60-100 parts of water are added, and after the stirring device is turned on, 4-12 parts of a polymerization monomer A and 0.1-3 parts of a crosslinking agent A for preparing the innermost core are added; then the temperature is raised to 60-80° C., and after the temperature stabilizes, 0.1-1 parts of an initiator is added to initiate the polymerization of the monomers; during the polymerization process, the temperature of the reactor 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 the temperature is kept at this temperature 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 reaction kettle, 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 completed, 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, after sufficient mixing, injecting the latex 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 liquid is set to 1:1-2, the temperature during the flocculation process is set at 65-95°C, and the flocculation time is 10-40 minutes.

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

[0023] Optionally, in step (1), the emulsifier is one or a mixture of potassium disproportionate rosin acid, potassium fatty acid, potassium oleate, sodium dodecyl sulfate, sodium dodecylbenzene sulfonate; the pH adjuster is one or a mixture of sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, potassium dihydrogen phosphate; the polymerization reaction monomer A is one or a mixture of styrene, acrylonitrile, methyl methacrylate, a-methylstyrene; the cross-linking agent is a compound having two or more double bonds in its structure, such as one or a mixture of divinylbenzene, ethylene glycol dimethacrylate, allyl methacrylate, dicyclopentadiene acrylate, triallyl isocyanurate; 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 in the redox initiator, and its composition includes ionic reducing agent ferrous sulfate; ion chelating agent sodium pyrophosphate or EDTA sodium salt; auxiliary reducing agent Rongalite, etc.; the specific ratio of the configured activator is not strictly limited, and its preferred mass ratio is ferrous sulfate: EDTA: Rongalite = 0.005: 0.3: 0.5; the oxidant is cumene hydroperoxide; the polymerization reaction monomer C is a mixture of styrene, a-methylstyrene, acrylonitrile, and methyl methacrylate, and the ratio is mixed according to the refractive index matching principle, and the specific mass ratio is styrene (or a-methylstyrene): acrylonitrile: methyl methacrylate = 20-50: 50-80: 0-10, and preferably the mass ratio is styrene (or a-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 above-mentioned prepared transparent ABS graft copolymer is less than 0.005, and the specific ratio thereof is the same as the ratio of the above-mentioned polymerized monomer C, and preferably the prepared copolymer of styrene, acrylonitrile and methyl methacrylate has a refractive index of 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 constructs a plastic core inside the rubber particles during the preparation of the rubber particles, then grafts and polymerizes the rubber particles on the surface, and adjusts the refractive index of the core inside the rubber particles to be consistent with the rubber phase, the graft layer phase, and the matrix resin phase to prepare a highly transparent ABS resin. Since the rubber particles used in the prepared transparent ABS resin contain a plastic core with strong rigidity, it is easier to induce and induce silver streaks during the stress process of the resin, promote the hollowing of the rubber particles, and thus better build a rigid-tough balance. In addition to having excellent light transmittance, the transparent ABS resin prepared by the present invention has a tensile strength far exceeding that of similar commercial 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 drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying 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 technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] The word "embodiment" used here as an "exemplary" does not necessarily mean that any embodiment described is superior to or better than other embodiments. Unless otherwise specified, the performance index tests in the embodiments of this application are performed using conventional test methods in the art. It should be understood that the terms described in this application are only used to describe specific implementation methods and are not used to limit the content disclosed in this application.

[0035] Unless otherwise specified, the technical and scientific terms used in this document 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 the present application, numerous specific details are provided in the specific examples below. It should be understood by those skilled in the art that the present application can also be implemented without certain specific details. In the embodiments, 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 the present application.

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

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

[0039] In order to better understand the present invention, the present invention is further specifically described below through the following examples, but it should not be understood as a limitation of the present invention. Some non-essential improvements and adjustments made by technicians in this field based on the above invention content are also considered to fall within the protection scope 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 is evacuated to a negative pressure, and after the air in the reactor is removed, 1 kg of fatty acid potassium soap and 2 kg of disproportionate rosin acid potassium soap as emulsifiers, 0.5 kg of sodium carbonate as a pH adjuster, and 60 kg of water are added. After the stirring device is turned on, 4 kg of polymerization monomers A (3 kg of methyl methacrylate and 1 kg of styrene) and 0.1 kg of divinylbenzene as a cross-linking agent for preparing the innermost core are added; the temperature is then raised to 65° C., and after the temperature stabilizes, 1 kg of potassium persulfate as an initiator is added to initiate the polymerization of the monomers; during the polymerization process, the reactor temperature is 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 an innermost core of a plastic phase and an outer layer of a rubber phase.

[0044] (3) 60 kg (dry basis) of the prepared latex was placed in a reactor, 150 kg of deionized water was added, 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, 0.1 kg of an oxidant cumene hydroperoxide was added, and 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) Add 1 part of an emulsion-type water-based antioxidant (the effective composition of the antioxidant is antioxidant 1076 and DLTP, with a mass ratio of 2:1) to 100 kg (dry basis) of the obtained ABS graft copolymer latex, mix them thoroughly, and then inject them into a 0.05% sulfuric acid aqueous solution for flocculation and demulsification; the ratio of ABS graft copolymer latex to sulfuric acid flocculation liquid is set to 1:2, the temperature during the flocculation process is set at 65°C, and the flocculation time is 40 min.

[0046] (5) After flocculation, the wet powder of transparent ABS graft copolymer can be obtained by centrifugal separation, and the wet ABS graft copolymer powder can be dried to obtain 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, and its specific composition is the same as that of polymer 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 disproportionate potassium rosin soap and 0.5 kg of sodium dodecyl sulfate were added as emulsifiers, 0.5 kg of sodium carbonate and 0.5 kg of sodium bicarbonate as pH adjusters, and 60 kg of water were added. After the stirring device was turned on, 8 kg of polymerization monomer 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 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 the polymerization of the monomers. During the polymerization process, the reactor temperature was maintained at 70° C. for 1 hour to prepare the innermost plastic core.

[0050] (2) Continue to add 52 kg of polymerization reaction monomer B butadiene into the reactor. The polymerization reaction monomer B butadiene is added by continuous dripping. During the feeding process, the polymerization temperature of the reactor is maintained at 70°C, and the monomer dripping time is controlled to be 3 hours. After the monomer dripping is completed, the temperature is raised to 85°C and kept warm for 2 hours to obtain a core layer 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, 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, 0.1 kg of oxidant cumene hydroperoxide was added, and 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 oxidant cumene hydroperoxide were added continuously, and the addition time was 2 hours. After the addition was completed, the system was heated to 85°C for aging for 1 hour to complete the emulsion grafting reaction, and a transparent ABS graft copolymer latex was obtained.

[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) is added to 100 kg (dry basis) of the obtained ABS graft copolymer latex. After sufficient mixing, the latex is injected into a 0.2% magnesium sulfate solution for flocculation and demulsification. The ratio of the ABS graft copolymer latex to the sulfuric acid flocculation liquid is set to 1:2. The temperature during the flocculation process is set at 75°C and the flocculation time is 30 min.

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

[0054] (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 1.515, and its specific composition was the same as that of polymer 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 transparent ABS resin.

[0055] Example 3

[0056] (1) The polymerization reactor was evacuated to negative pressure, and the air in the reactor was removed. Then, 1 kg of potassium oleate and 1 kg of disproportionate potassium soap and 0.5 kg of sodium dodecylbenzene sulfonate were added 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 crosslinking agent were added. Then, the temperature was raised to 65°C, and after the temperature was stabilized, 0.7 kg of ammonium persulfate as initiator was added to initiate the polymerization of the monomers. During the polymerization process, the reactor temperature was maintained at 70°C for 1 hour. The innermost plastic core was prepared.

[0057] (2) Continue to add 48 kg of polymerization reaction monomer B isoprene into the reactor. The polymerization reaction monomer B isoprene is added by continuous dripping. During the feeding process, the polymerization temperature of the reactor is maintained at 70°C, and the monomer dripping time is controlled to be 1 hour. After the monomer dripping is completed, the temperature is raised to 85°C and kept warm for 2 hours to obtain a core layer latex with the innermost core being a plastic phase and the outer layer being a rubber phase.

[0058] (3) 60 kg (dry basis) of the prepared latex was placed in a reactor, 150 kg of deionized water was added, 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 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, and a transparent ABS graft copolymer latex was obtained.

[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) is added to 100 kg (dry basis) of the obtained ABS graft copolymer latex. After sufficient mixing, the latex is injected into a 0.2% magnesium sulfate solution for flocculation and demulsification. The ratio of the ABS graft copolymer latex to the sulfuric acid flocculation liquid is set to 1:2. The temperature during the flocculation process is set at 75°C and the flocculation time is 30 min.

[0060] (5) After flocculation, the wet powder of transparent ABS graft copolymer can be obtained by centrifugal separation, and the wet ABS graft copolymer powder can be dried to obtain 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 24:70:6) prepared by bulk polymerization or suspension polymerization to obtain transparent ABS resin.

[0062] Example 4

[0063] (1) The polymerization reactor was evacuated to negative pressure, and the air in the reactor was removed. Then, 1 kg of potassium oleate and 1 kg of disproportionate potassium soap and 0.5 kg of sodium dodecylbenzene sulfonate were added 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 crosslinking agent were added. Then, the temperature was raised to 65°C, and after the temperature was stabilized, 0.7 kg of ammonium persulfate as initiator was added to initiate the polymerization of the monomers. During the polymerization process, the reactor temperature was maintained at 70°C for 1 hour. The innermost plastic core was prepared.

[0064] (2) Continue to add 48 kg of polymerization reaction monomer B butadiene into the reactor. The polymerization reaction monomer B butadiene is added by continuous dripping. During the feeding process, the polymerization temperature of the reactor is maintained at 70°C, and the monomer dripping time is controlled to 1 hour. After the monomer dripping is completed, the temperature is raised to 85°C and kept warm for 2 hours to obtain a core layer 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 prepared latex was placed in a reactor, 150 kg of deionized water was added, 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: 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 for aging for 1 hour to complete the emulsion grafting reaction, and a transparent ABS graft copolymer latex was obtained.

[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) is added to 100 kg (dry basis) of the obtained ABS graft copolymer latex. After sufficient mixing, the latex is injected into a 0.2% magnesium sulfate solution for flocculation and demulsification. The ratio of the ABS graft copolymer latex to the sulfuric acid flocculation liquid is set to 1:2. The temperature during the flocculation process is set at 75°C and the flocculation time is 30 min.

[0067] (5) After flocculation, the wet powder of transparent ABS graft copolymer can be obtained by centrifugal separation, and the wet ABS graft copolymer powder can be dried to obtain 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 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 disproportionate potassium rosin soap and 0.5 kg of sodium dodecylbenzene sulfonate were added 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, 4 kg of polymerization monomer 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 a crosslinking agent were added. The temperature was then raised to 65° C., and after the temperature was stabilized, 0.7 kg of ammonium persulfate as an initiator was added to initiate the polymerization of the monomers. During the polymerization process, the reactor temperature was maintained at 70° C. for 1 hour to prepare the innermost plastic core.

[0071] (2) Continue to add 42 kg of polymerization monomer B butadiene and 14 kg of styrene into the reactor. The polymerization monomer B butadiene and styrene are added by continuous dripping. During the feeding process, the polymerization temperature of the reactor is maintained at 70°C, and the monomer dripping time is controlled at 6 hours. After the monomer dripping is completed, the temperature is raised to 85°C and kept warm for 2 hours to obtain a core layer latex with an innermost core layer of a plastic phase and an outer layer of a rubber phase.

[0072] (3) 60 kg (dry basis) of the prepared latex was placed in a reactor, 150 kg of deionized water was added, 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 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) is added to 100 kg (dry basis) of the obtained ABS graft copolymer latex. After sufficient mixing, the latex is injected into a 0.5% magnesium sulfate solution for flocculation and demulsification. The ratio of the ABS graft copolymer latex to the sulfuric acid flocculation liquid is set to 1:2. The temperature during the flocculation process is set at 85°C and the flocculation time is 20 min.

[0074] (5) After flocculation, the wet powder of transparent ABS graft copolymer can be obtained by centrifugal separation, and the wet ABS graft copolymer powder can be dried to obtain 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 41:53:6) prepared by bulk polymerization or suspension polymerization to obtain transparent ABS resin.

[0076] Example 6

[0077] (1) The polymerization reactor is evacuated to a negative pressure, and after the air in the reactor is removed, 1 kg of potassium oleate and 1 kg of disproportionate potassium rosin 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 are added. After the stirring device is turned on, 8 kg of polymerization monomer 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 crosslinking agent are added; the temperature is then raised to 65° C., and after the temperature is stabilized, 0.7 kg of ammonium persulfate as initiator is added to initiate the polymerization of the monomers; during the polymerization process, the reactor temperature is 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 dripping. During the feeding process, the polymerization temperature of the reactor is maintained at 70°C, and the monomer dripping time is controlled to 4 hours. After the monomer dripping is completed, the temperature is raised to 85°C and kept warm for 2 hours to obtain a core layer latex with an innermost core layer of a plastic phase and an outer layer of a rubber phase.

[0079] (3) 60 kg (dry basis) of the prepared latex was placed in a reactor, 150 kg of deionized water was added, 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 for aging for 1 hour to complete the emulsion grafting reaction, and a transparent ABS graft copolymer latex was obtained.

[0080] (4) 1 kg of 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, and after sufficient mixing, it was injected into a 0.5% magnesium sulfate solution for flocculation and demulsification. The ratio of ABS graft copolymer latex to sulfuric acid flocculation liquid was set to 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 transparent ABS graft copolymer can be obtained by centrifugal separation, and the wet ABS graft copolymer powder can be dried to obtain 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, copolymer composition is the same as monomer C, specific ratio is styrene: methyl methacrylate: acrylonitrile mass ratio 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 used 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 content 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 specimens based on ASTM D256 (2010), ASTM D 638 (2014) and ISO13468-2 (1999) for testing, and the test results are shown in the following table. For comparison, transparent ABS resin TR-558 from LG Company of South Korea and transparent ABS PA-758 from Chi Mei Company of Taiwan, China were selected as comparative examples 1 and 2 respectively during the test, and the specific results are shown in the following table:

[0085]

[0086]

[0087] From the test results, it can be observed that the light transmittance and haze value of the transparent ABS resin prepared by the present invention are comparable to those of commercial products, and the light transmittance is higher than that of commercial products. The impact strength and tensile strength of Examples 1, 2, and 5 of the prepared transparent ABS resin in mechanical properties are higher than those of commercial products, and the transparent ABS resin has a better balance of rigidity and toughness.

[0088] It is worth noting that by constructing a plastic core inside the rubber particles, the rigidity of the final transparent ABS resin can be improved without affecting the transparency. The efficiency of improving the rigidity varies depending on the content of the plastic core in the core layer. Isoprene can replace butadiene to prepare transparent ABS resin, but because its own glass transition temperature is higher than that of polybutadiene, its toughening efficiency is poorer than that of butadiene. When styrene partially replaces butadiene as the rubber phase in transparent ABS, the light transmittance of the transparent ABS resin prepared therefrom is basically unaffected, but its impact strength will decrease.

[0089] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be 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 will not be limited to the embodiments shown herein, but rather 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: The transparent ABS resin 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 grafted layer; 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.

2. A method for preparing a high-toughness, high-rigidity transparent ABS resin as claimed in claim 1, characterized in that: The specific steps are as follows: (1) After the reactor is emptied, 1-3 parts of an emulsifier, 0.1-2 parts of a pH adjuster and 60-100 parts of water are added, and 4-12 parts of a polymerization monomer A and 0.1-3 parts of a crosslinking agent A for preparing the innermost core are added while stirring; then the temperature is raised, and after the temperature stabilizes, 0.1-1 parts of an initiator is added to initiate polymerization of the monomers to prepare the innermost plastic core; (2) continuously adding 40-60 parts of the polymerization reaction monomer B to the reaction kettle of step (1), and heating the reaction after the monomer addition is completed to obtain a core layer latex having an innermost core layer of a plastic phase and an outer layer of a rubber phase; (3) taking 50-70 parts (dry basis) of the core layer latex prepared in step (2) into a reaction kettle, adding 100-150 parts of deionized water, heating and adding 1-3 parts of an activator and 0.1-1 parts of an oxidant; then continuously dripping 30-50 parts of a polymerization reaction monomer C and 0.1-1 parts of an oxidant; after the dripping is complete, heating the system, aging it, and then completing the emulsion grafting reaction to obtain a transparent ABS graft copolymer latex; (4) adding 1 part of an emulsion-type water-based antioxidant to 100 parts (dry basis) of the ABS graft copolymer latex obtained in step (3), mixing them thoroughly, and then injecting a 0.05-0.5% sulfuric acid or magnesium sulfate aqueous solution for flocculation and demulsification; centrifugation and drying are performed to obtain a transparent ABS graft copolymer; (5) melt-extrude and blend 15-30 parts of the transparent ABS graft copolymer powder obtained in step (4) with 70-85 parts of MSAN resin prepared by bulk polymerization or suspension polymerization to finally obtain the transparent ABS resin with high toughness and high rigidity.

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

4. 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 1-3h.

5. The method for preparing a high-toughness, high-rigidity transparent ABS resin according to claim 2, characterized in that: 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.

6. The method for preparing a high-toughness, high-rigidity transparent ABS resin according to claim 2 or 5, characterized in that: In step (2), the monomer is added dropwise for 1-6 hours. After the addition is completed, the temperature of the reactor is increased to 80-95° C. and the reaction time is 2-3 hours.

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; ion chelating agent sodium pyrophosphate or EDTA sodium salt; auxiliary reducing agent Rongalite, etc.; the specific ratio of the configured activator is not strictly limited, and its preferred mass ratio is ferrous sulfate: EDTA: Rongalite = 0.005: 0.3: 0.5; the oxidant is cumene hydroperoxide; the polymerization reaction monomer C is a mixture of styrene, a-methylstyrene, acrylonitrile, and methyl methacrylate, and the ratio is mixed according to the refractive index matching principle, and the specific ratio is styrene (or a-methylstyrene): acrylonitrile: methyl methacrylate is 20-50: 50-80: 0-10, and as a preferred ratio, the ratio of styrene (or a-methylstyrene): acrylonitrile: methyl methacrylate is 24: 70: 6 or 41: 53:

6.

8. 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.

9. The method for preparing a transparent ABS resin with high toughness and high rigidity according to claim 2, characterized in that: The composition of the emulsion type water-based antioxidant is 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 polymerized from styrene, acrylonitrile and methyl methacrylate and has a refractive index difference of less than 0.005 with the refractive index of the transparent ABS graft copolymer prepared above; 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.

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

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