Transparent ABS resin with net-shaped structure body and preparation method of transparent ABS resin

Abstract

The invention belongs to the technical field of preparation of high polymer materials, and particularly relates to transparent ABS resin with a net structure and a preparation method of the transparent ABS resin. The preparation method comprises the following steps: synthesizing ABS resin by adopting a bulk polymerization method, putting a certain part of solution-polymerized butadiene-styrene rubber into a mixed solution of a monomer and a solvent, stirring, injecting the solution-polymerized butadiene-styrene rubber, a certain part of an initiator and a chain transfer agent into a reaction kettle after the solution-polymerized butadiene-styrene rubber is completely dissolved, and polymerizing under the external conditions of applying shearing force and temperature. The two-phase refractive index is adjusted by controlling the monomer proportion and the polymerization speed, the phase region structure is controlled by controlling the stirring speed and the system viscosity, a net-shaped phase region structure and rubber particles with different sizes are prepared, the rubber particles are internally provided with inner containing structures, the problem that transparent ABS resin is insufficient in mechanical property is solved, and the mechanical property of the transparent ABS resin is improved. The light transmittance of the finally obtained resin is higher than 89%, and the notched impact strength of a cantilever beam is larger than 265 J / m.

Description

Technical Field

[0001] The invention relates to the technical field of polymer compounds, and particularly discloses a network-structured body transparent ABS resin and a preparation method thereof. Background Art

[0002] Transparent ABS resin is a specialty resin developed from general-purpose ABS resin. It possesses excellent mechanical properties while also meeting light transmission requirements, making it an indispensable new polymer material in our daily lives. As the specialty resin with the highest added value in the ABS product family, it has long been valued by ABS resin manufacturers.

[0003] The greatest challenge in the industrial production of transparent ABS resin lies in the difficulty in balancing optical and mechanical properties, which significantly limits its application. Transparent ABS resin consists of a dispersed rubber phase and a continuous phase composed of MSAN resin. There are two common approaches to achieving optical transparency in ABS resin: one is to control the size of the toughening particles to be less than one-tenth the wavelength of visible light. This small enough particle size minimizes light obstruction, allowing each phase to optically converge into a single phase, achieving optical transparency. The other approach is to achieve high transmittance by matching the refractive indices of the phase regions, minimizing refraction and scattering of light at the interfaces. While the former approach can achieve a certain degree of optical transparency, it compromises the excellent mechanical properties of the ABS resin. Therefore, it is particularly important to improve the impact toughness of transparent ABS resin by matching the refractive indices of the phases, while not compromising optical properties.

[0004] Currently, existing methods for improving the impact strength of transparent ABS resin mainly involve mixing with other fillers. Patent CN107109027A improves the impact strength by adding glass fillers such as silica, alumina, boron oxide, and calcium oxide, but the addition of glass fillers inevitably leads to a decrease in optical properties. Patent CN108530822A improves the impact strength of transparent ABS resin by adding low-density polyethylene and inorganic silica gel, but the addition of other fillers always leads to a disadvantage of decreased optical properties.

[0005] Therefore, without adding any additives that affect the optical properties, it is of great practical significance to improve the impact strength of transparent ABS resin by controlling the viscosity of the system to obtain a phase structure in which a network and rubber particles coexist. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to design a phase structure in which a network and rubber particles coexist without adding any additives that affect optical properties, so as to prepare a transparent ABS resin with excellent light transmittance and impact resistance.

[0007] The technical solution adopted in the present invention is as follows:

[0008] In a first aspect, the present invention provides a method for preparing a transparent ABS resin having a network structure, which specifically comprises the following steps:

[0009] S1: Take the following parts by weight of transparent ABS resin component raw materials: 15-35 parts by weight of organic solvent, 5.2-9 parts by weight of rubber, and 57.2-89 parts by weight of monomer;

[0010] The monomers specifically include the following components: 14.75 to 37.75 parts by mass of vinylbenzene monomers, 4.25 to 12.25 parts by mass of vinyl cyanide monomers, and 30 to 47 parts by mass of ethylene unsaturated carboxylate monomers;

[0011] The rubber is a solution-polymerized butadiene-styrene rubber;

[0012] S2: crushing the rubber and placing it in a mixture of monomer and organic solvent, stirring it, and injecting it into the mixture together with 0.03-0.1% by weight of the monomer as an initiator and 0.3-1% by weight of the monomer as a chain transfer agent after it is completely dissolved; heating the mixture to 120-140° C., stirring and polymerizing it at 50-100 rpm in an oxygen-free environment for not less than 1.5 hours; after the reaction is completed, devolatilizing and extruding it to obtain a transparent ABS resin with a network structure;

[0013] The addition of chain transfer agent can shorten the resin chain, reduce the degree of resin chain entanglement, reduce the molecular weight of the resin phase, and reduce the viscosity, which can greatly slow down the speed at which the rubber chains curl up into rubber particles.

[0014] Preferably, in step S2, the mixed solution is heated to 120-140° C. at a rate of 1.5-2.5° C. / min.

[0015] Preferably, the vinylbenzene monomer is any one of styrene, methylstyrene, p-methylstyrene and vinyltoluene, or a mixture of two or more thereof.

[0016] Preferably, the vinyl cyanide monomer is any one of acrylonitrile and methacrylonitrile, or a mixture of the two.

[0017] Preferably, the ethylene unsaturated carboxylate monomer is any one of methyl acrylate, ethyl acrylate, butyl acrylate, and methyl methacrylate, or a mixture of two or more thereof.

[0018] Preferably, the initiator is one of cumene hydroperoxide, di-tert-butyl peroxide, potassium persulfate, and azobisisobutyronitrile.

[0019] Preferably, the chain transfer agent is any one of tert-dodecyl mercaptan, n-dodecyl mercaptan, and n-propyl mercaptan, or a mixture of two or more thereof.

[0020] Preferably, the chain transfer agent is tert-dodecyl mercaptan, the initiator is di-tert-butyl peroxide, the vinylbenzene monomer is styrene, the vinyl cyanide monomer is acrylonitrile, the ethylene unsaturated carboxylate monomer is methyl methacrylate, and the organic solvent is ethylbenzene.

[0021] In a second aspect, the present invention provides a network structure body transparent ABS resin prepared by the method described in the first aspect.

[0022] Preferably, the transparent ABS resin has a network structure and a phase structure in which large and small rubber particles coexist, the rubber particles have an internal inclusion structure, and the number average molecular weight of the resin phase is 75,000 to 85,000.

[0023] The beneficial effects achieved by the present invention are:

[0024] The key to this invention is adjusting the refractive index of the two phases by controlling the monomer ratio and polymerization rate. By varying the system viscosity, the speed at which rubber chains curl into rubber particles is controlled, thereby manipulating the resulting phase structure. The ABS resin prepared in this invention has a final light transmittance exceeding 90% and an Izod notched impact strength exceeding 260 J / m. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a transmission electron microscope image of the ABS resin prepared in Example 1 of the present invention.

[0026] Figure 2 is a transmission electron microscope image of the ABS resin prepared in Comparative Example 1 of the present invention.

[0027] Figure 3 is a transmission electron microscope image of the ABS resin prepared in Comparative Example 5 of the present invention. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of the present invention more clear and distinct, the present invention is further described in detail with reference to the following examples. It should be noted that the present invention is not limited to the following examples.

[0029] In the following examples and comparative examples, the rubber used was 1322 rubber from the same batch.

[0030] Example 1

[0031] First, 7 parts by weight of rubber, 17 parts by weight of styrene, 5.7 parts by weight of acrylonitrile, 40.3 parts by weight of methyl methacrylate, and 30 parts by weight of ethylbenzene were added to a reactor in proportion. Stirring was carried out at room temperature for 6 hours. Then, the initiators di-tert-butyl peroxide and tert-dodecyl mercaptan were added. The amount of di-tert-butyl peroxide added was 0.05% by weight of the total monomer volume, and the amount of tert-dodecyl mercaptan added was 0.5% by weight of the total monomer volume. Before the reaction, nitrogen was purged from the reactor to eliminate the effects of oxygen on the reaction system. After checking the reactor for leaks and confirming a good seal, stirring was increased to 77 rpm. The temperature was raised in a circulating oil bath at a rate of 2°C / min, reaching 130°C in 55 minutes. The reaction was continued for 2 hours. After completion of the reaction, the product was extruded after devolatilization. The resulting transparent ABS resin has an impact strength, transmittance, haze, molecular weight, and conversion rate, as listed in Table 1.

[0032] Example 2

[0033] First, 8.8 parts by weight of rubber, 24.6 parts by weight of styrene, 8.3 parts by weight of acrylonitrile, 56.1 parts by weight of methyl methacrylate, and 20 parts by weight of ethylbenzene were added to a reactor in the appropriate proportions. Stirring was carried out at room temperature for 6 hours. Then, the initiators di-tert-butyl peroxide and tert-dodecyl mercaptan were added. The amount of di-tert-butyl peroxide added was 0.05% by weight of the total monomer volume, and the amount of tert-dodecyl mercaptan added was 0.5% by weight of the total monomer volume. Before the reaction, nitrogen was purged from the reactor to eliminate any oxygen contamination. After checking the reactor for leaks and confirming a good seal, stirring was increased to 77 rpm. The temperature was raised in a circulating oil bath at 2°C / min, reaching 130°C in 55 minutes. The reaction was continued for 2 hours. After completion of the reaction, the product was extruded after devolatilization. The resulting transparent ABS resin has an impact strength, transmittance, haze, molecular weight, and conversion rate, as listed in Table 1.

[0034] Comparative Example 1

[0035] First, 7 parts by weight of rubber, 28.35 parts by weight of styrene, 9.45 parts by weight of acrylonitrile, 25.2 parts by weight of methyl methacrylate, and 30 parts by weight of ethylbenzene were added to a reactor in the appropriate proportions. Stirring was carried out at room temperature for 6 hours. Then, the initiators di-tert-butyl peroxide and tert-dodecyl mercaptan were added. The amount of di-tert-butyl peroxide added was 0.05% by weight of the total monomer volume, and the amount of tert-dodecyl mercaptan added was 0.5% by weight of the total monomer volume. Before the reaction, nitrogen was purged from the reactor to eliminate any oxygen contamination. After checking the reactor for leaks and confirming a good seal, stirring was increased to 77 rpm. The temperature was raised in a circulating oil bath at 2°C / min, reaching 130°C in 55 minutes. The reaction was continued for 2 hours. After completion of the reaction, the product was extruded after devolatilization. The resulting transparent ABS resin is shown in Table 1 for its impact strength, transmittance, haze, molecular weight, and conversion.

[0036] Comparative Example 2

[0037] First, 7 parts by weight of rubber, 17 parts by weight of styrene, 5.7 parts by weight of acrylonitrile, 40.3 parts by weight of methyl methacrylate, and 30 parts by weight of ethylbenzene were added to a reactor in the appropriate proportions. Stirring was carried out at room temperature for 6 hours. Then, the initiators di-tert-butyl peroxide and tert-dodecyl mercaptan were added. The amount of di-tert-butyl peroxide added was 0.05% by weight of the total monomer volume, and the amount of tert-dodecyl mercaptan added was 0.5% by weight of the total monomer volume. Before the reaction, nitrogen was purged from the reactor to eliminate any oxygen contamination. After checking the reactor for leaks and confirming a good seal, stirring was increased to 77 rpm. The temperature was raised in a circulating oil bath at 2°C / min, reaching 150°C in 65 minutes. The reaction was continued for 2 hours. After completion of the reaction, the product was extruded after devolatilization. The resulting transparent ABS resin is shown in Table 1 for its impact strength, transmittance, haze, molecular weight, and conversion.

[0038] Comparative Example 3

[0039] First, 7 parts by weight of rubber, 17 parts by weight of styrene, 5.7 parts by weight of acrylonitrile, 40.3 parts by weight of methyl methacrylate, and 30 parts by weight of ethylbenzene were added to a reactor in proportion. Stirring was carried out at room temperature for 6 hours. Then, the initiators di-tert-butyl peroxide and tert-dodecyl mercaptan were added. The amount of di-tert-butyl peroxide added was 0.05% by weight of the total monomer volume, and the amount of tert-dodecyl mercaptan added was 0.5% by weight of the total monomer volume. Before the reaction, nitrogen was purged from the reactor to eliminate the effects of oxygen on the reaction system. After checking the reactor for leaks and confirming a good seal, stirring was increased to 77 rpm. The temperature was raised in a circulating oil bath at a rate of 0.5°C / min, reaching 130°C in 210 minutes. The reaction was continued for 2 hours. After completion of the reaction, the product was extruded after devolatilization. The resulting transparent ABS resin has an impact strength, transmittance, haze, molecular weight, and conversion rate, as listed in Table 1.

[0040] Comparative Example 4

[0041] First, 7 parts by weight of rubber, 17 parts by weight of styrene, 5.7 parts by weight of acrylonitrile, 40.3 parts by weight of methyl methacrylate, and 30 parts by weight of ethylbenzene were added to a reactor in proportion. Stirring was carried out at room temperature for 6 hours. Then, the initiators di-tert-butyl peroxide and tert-dodecyl mercaptan were added. The amount of di-tert-butyl peroxide added was 0.05% by weight of the total monomer volume, and the amount of tert-dodecyl mercaptan added was 0.5% by weight of the total monomer volume. Before the reaction, nitrogen was purged from the reactor to eliminate the effects of oxygen on the reaction system. After checking the reactor for leaks and confirming a good seal, stirring was increased to 77 rpm. The temperature was raised in a circulating oil bath at a rate of 2°C / min, reaching 130°C in 55 minutes. The reaction was continued for 2 hours. After completion of the reaction, the product was extruded after devolatilization. The resulting transparent ABS resin has an impact strength, transmittance, haze, molecular weight, and conversion rate, as listed in Table 1.

[0042] Comparative Example 5

[0043] First, 7 parts by weight of rubber, 17 parts by weight of styrene, 5.7 parts by weight of acrylonitrile, 40.3 parts by weight of methyl methacrylate, and 30 parts by weight of ethylbenzene were added to a reactor in proportion. Stirring was carried out at room temperature for 6 hours. Then, the initiators di-tert-butyl peroxide and tert-dodecyl mercaptan were added. The amount of di-tert-butyl peroxide added was 0.05% by weight of the total monomer volume, and the amount of tert-dodecyl mercaptan added was 0.5% by weight of the total monomer volume. Before the reaction, nitrogen was purged from the reactor to eliminate the effects of oxygen on the reaction system. After checking the reactor for leaks and confirming a good seal, stirring was increased to 231 rpm. The temperature was raised in a circulating oil bath at 2°C / min, reaching 130°C in 55 minutes. The reaction was continued for 2 hours. After completion of the reaction, the product was extruded after devolatilization. The resulting transparent ABS resin has an impact strength, transmittance, haze, molecular weight, and conversion rate, as listed in Table 1.

[0044] Comparative Example 6

[0045] First, 7 parts by weight of rubber, 17 parts by weight of styrene, 5.7 parts by weight of acrylonitrile, 40.3 parts by weight of methyl methacrylate, and 30 parts by weight of ethylbenzene were added to a reactor in proportion. Stirring was carried out at room temperature for 6 hours. Then, the initiators di-tert-butyl peroxide and tert-dodecyl mercaptan were added. The amount of di-tert-butyl peroxide added was 0.05% by weight of the total monomer volume, and the amount of tert-dodecyl mercaptan added was 0.1% by weight of the total monomer volume. Before the reaction, nitrogen was purged from the reactor to eliminate the effects of oxygen on the reaction system. After checking the reactor for leaks and confirming a good seal, stirring was increased to 231 rpm. The temperature was raised in a circulating oil bath at 2°C / min, reaching 130°C in 55 minutes. The reaction was continued for 2 hours. After completion of the reaction, the product was extruded after devolatilization. The resulting transparent ABS resin has an impact strength, transmittance, haze, molecular weight, and conversion rate, as listed in Table 1.

[0046] Table 1 Characteristic parameters of transparent ABS resin in Examples and Comparative Examples

[0047]

[0048] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing a transparent ABS resin with a network structure, characterized in that: The following steps are involved: S1: Take the following parts by weight of transparent ABS resin component raw materials: 15-35 parts by weight of organic solvent, 5.2-9 parts by weight of rubber, and 57.2-89 parts by weight of monomer; The monomers specifically include the following components: 14.75 to 37.75 parts by mass of vinylbenzene monomers, 4.25 to 12.25 parts by mass of vinyl cyanide monomers, and 30 to 47 parts by mass of ethylene unsaturated carboxylate monomers; The rubber is a solution-polymerized butadiene-styrene rubber; S2: crushing the rubber and placing it in a mixture of monomer and organic solvent, stirring it, and injecting it into the mixture together with 0.03-0.1% of the monomer weight of the initiator and 0.3-1% of the monomer weight of the chain transfer agent after it is completely dissolved; After the mixed liquid is heated to 120-140° C., it is stirred and polymerized in an oxygen-free environment. After the reaction is completed, the mixed liquid is extruded and discharged to obtain a transparent ABS resin with a network structure.

2. The method for preparing a transparent ABS resin having a network structure according to claim 1, wherein: In step S2, the mixed solution is heated to 120-140° C. at a rate of 1.5-2.5° C. / min.

3. The method for preparing a transparent ABS resin having a network structure according to claim 1, wherein: The vinylbenzene monomer is any one of styrene, methylstyrene, p-methylstyrene and vinyltoluene, or a mixture of two or more thereof.

4. The method for preparing a transparent ABS resin having a network structure according to claim 1, wherein: The vinyl cyanide monomer is any one of acrylonitrile and methacrylonitrile or a mixture of the two.

5. The method for preparing a transparent ABS resin having a network structure according to claim 1, wherein: The ethylene unsaturated carboxylate monomer is any one of methyl acrylate, ethyl acrylate, butyl acrylate, and methyl methacrylate, or a mixture of two or more thereof.

6. The method for preparing a transparent ABS resin having a network structure according to claim 1, wherein: The initiator is one of cumene hydroperoxide, di-tert-butyl peroxide, potassium persulfate, and azobisisobutyronitrile.

7. The method for preparing a transparent ABS resin having a network structure according to claim 1, wherein: The chain transfer agent is any one of tert-dodecyl mercaptan, n-dodecyl mercaptan, and n-propyl mercaptan, or a mixture of two or more thereof.

8. The method for preparing a transparent ABS resin having a network structure according to claim 1, wherein: The chain transfer agent is tert-dodecyl mercaptan, the initiator is di-tert-butyl peroxide, the vinylbenzene monomer is styrene, the vinyl cyanide monomer is acrylonitrile, the ethylene unsaturated carboxylic acid ester monomer is methyl methacrylate, and the organic solvent is ethylbenzene.

9. A transparent ABS resin with a network structure prepared by the method according to any one of claims 1 to 8.

10. The transparent ABS resin of the mesh structure body according to claim 9, characterized in that: The transparent ABS resin has a network structure and a phase structure in which large and small rubber particles coexist. The rubber particles have an internal inclusion structure. The number average molecular weight of the resin phase is 75,000-85,000.

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