A transparent high-impact heat-resistant MBS resin and its preparation method

Abstract

The present invention provides a transparent high-impact heat-resistant MBS resin and a preparation method thereof, which relates to the field of preparation methods of polymer materials and is prepared from the following raw materials: water, ethanol, maleic anhydride, emulsifier, MBS resin graft latex, potassium persulfate, antioxidant; the MBS resin graft latex is prepared from the following raw materials: water, modified styrene-butadiene latex, sodium bisulfite, potassium persulfate, methyl methacrylate and styrene; the modified styrene-butadiene latex is prepared from the following raw materials: pre-emulsion, glycidyl methacrylate, ammonium persulfate, divinylbenzene, potassium persulfate; the pre-emulsion is prepared from the following raw materials: water, emulsifier, butadiene and styrene. The product of the present invention has good heat resistance, good modification effect on PVC, and the modified PVC composite material has high light transmittance, high cantilever beam impact strength and good aging resistance.

Description

Technical Field

[0001] The invention relates to the field of polymer material preparation methods, and in particular to a transparent high-impact heat-resistant MBS resin and a preparation method thereof. Background Art

[0002] MBS (Methyl Methacrylate-Butadiene-Styrene) resin is a terpolymer composed of methyl methacrylate (M), butadiene (B) and styrene (S), with a typical core-shell structure. It can be used to improve the toughness and processing properties of plastics such as PVC, and is commonly used in packaging, medical devices, automotive accessories and other fields. At present, the core advantages of MBS resin are concentrated on transparency, biosafety and processing convenience, and it is especially suitable for disposable transparent devices and packaging. In the case where transparency and impact resistance must be taken into account, its application in high temperature environments is limited due to its lack of heat resistance.

[0003] The prior art with publication number CN108912275B discloses a method for preparing a transparent high-impact MBS resin, which constructs a bimodal clustered particle structure by synthesizing small-particle styrene butadiene latex (about 100 nm) and synthesizing large-particle latex (about 300 nm) induced by an agglomerating agent, thereby achieving the invention purpose of ensuring high transparency with small-particle latex and providing high impact resistance with large-particle latex, and solving the problem that the two properties of traditional MBS resin cannot be achieved at the same time. However, this technical solution does not improve the heat resistance of MBS resin.

[0004] The prior art with publication number CN111072865B discloses a method for preparing MBS resin using sodium alkyl acrylic acid sulfonate as an emulsifier, and the MBS resin prepared by the method is used to modify PVC, and the obtained PVC modified resin has better processability and anti-sticking properties. However, the heat resistance of the MBS resin is not improved.

[0005] It can be seen that the MBS resin in the prior art has the following technical defects: poor heat resistance and poor modification effect on PVC. Summary of the invention

[0006] In view of the deficiencies in the prior art, the present invention aims to provide a transparent, high-impact, heat-resistant MBS resin and a preparation method thereof, and to achieve the following invention objectives: the prepared MBS resin has better heat resistance and good modification effect on PVC, and the modified PVC composite material has high light transmittance, high cantilever beam impact strength and aging resistance.

[0007] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0008] A transparent high-impact heat-resistant MBS resin is prepared from the following raw materials: water, ethanol, maleic anhydride, emulsifier, MBS resin graft latex, potassium persulfate, and antioxidant;

[0009] The MBS resin graft latex is prepared from the following raw materials: water, modified styrene-butadiene latex, sodium bisulfite, potassium persulfate, methyl methacrylate, and styrene, and the mass ratio is (300 - 400): (80 - 100): (0.3 - 1.2): (0.5 - 1.0): 100: (60 - 70);

[0010] The modified styrene-butadiene latex is prepared from the following raw materials: pre-emulsion, glycidyl methacrylate, ammonium persulfate, divinylbenzene, potassium persulfate, and the mass ratio is 100: (5 - 10): (0.2 - 0.5): (4 - 6): (0.3 - 0.8);

[0011] The pre-emulsion is prepared from the following raw materials: water, emulsifier, butadiene, and styrene.

[0012] Furthermore, the mass ratio of the water, ethanol, maleic anhydride, emulsifier, MBS resin graft latex, potassium persulfate, and antioxidant is (300 - 400): (30 - 40): (25 - 35): (5 - 10): 100: (1.0 - 1.5): (1.0 - 2.0);

[0013] Furthermore, the raw materials of the pre-emulsion: the mass ratio of water, emulsifier, butadiene, and styrene is 100: (1.5 - 3.0): (12 - 18): (8 - 12);

[0014] Furthermore, the emulsifier is any one of sodium dodecyl sulfate and sodium dodecylbenzenesulfonate.

[0015] A preparation method of a transparent high-impact heat-resistant MBS resin includes the following steps: pre-emulsification, gradient cross-linking synthesis of modified styrene-butadiene latex, graft synthesis of MBS resin latex, and heat-resistant monomer modification of the graft shell layer.

[0016] The pre-emulsification:

[0017] Add water and emulsifier into the reaction kettle, stir at a speed of 250 - 350 r / min at room temperature, displace the air in the system with nitrogen, add butadiene and styrene, and continue stirring for 25 min - 35 min to obtain the pre-emulsion.

[0018] The gradient cross-linking synthesis of modified styrene-butadiene latex:

[0019] Divide the pre-emulsion into two parts, and the mass ratio of the first part of the pre-emulsion to the second part of the pre-emulsion is 1: (2 - 3); Divide the divinylbenzene into 4 - 6 equal parts.

[0020] Add the first portion of the pre-emulsion into the reaction kettle, introduce nitrogen to displace the air in the reaction kettle, stir at a rotation speed of 250 - 350 r / min at 65 - 75 °C, add glycidyl methacrylate, ammonium persulfate and 1 portion of divinylbenzene, and carry out constant-temperature stirring reaction for 2 - 3 h; continuously feed the second portion of the pre-emulsion below the liquid level in the kettle, and the feeding time is 2 - 3 h. Among them, after adding the second portion of the pre-emulsion for 30 - 40 min, add the remaining divinylbenzene in portions, add it once every 20 - 30 min, and add 1 portion of divinylbenzene each time. After the addition is completed, react for 30 - 40 min; raise the temperature of the reaction system to 80 - 85 °C, add potassium persulfate, and stir and react for 2.5 - 4 h; centrifuge to obtain the modified styrene-butadiene latex for standby.

[0021] The graft copolymerized MBS resin latex:

[0022] Mix potassium persulfate and methyl methacrylate according to the mass ratio of (0.5 - 1.0):20 to obtain mixture A.

[0023] Mix methyl methacrylate and styrene according to the mass ratio of 80:(60 - 70) to obtain mixture B.

[0024] Add water, the modified styrene-butadiene latex and sodium bisulfite into the reaction kettle, stir at a rotation speed of 250 - 350 r / min at 70 - 80 °C for 8 - 12 min, then add mixture A, and dropwise add mixture B with a peristaltic pump. The dropping time is 2 - 2.5 h, and carry out constant-temperature stirring reaction; obtain the MBS resin latex.

[0025] The heat-resistant monomer modified graft shell layer:

[0026] Ultrasonically disperse ethanol, maleic anhydride and emulsifier for 5 - 10 min, add water and then ultrasonically disperse for 10 - 30 min to form a uniform maleic anhydride emulsion for standby; add the MBS resin latex into the reaction kettle, and set the stirring rate to 300 - 400 r / min; dropwise add the maleic anhydride emulsion with a peristaltic pump, and the dropping time is 1 - 2 h; after the dropping is completed, use nitrogen to displace the air in the reaction kettle, raise the temperature of the reaction system to 70 - 80 °C, add potassium persulfate, and carry out constant-temperature stirring reaction for 2 - 4 h; add antioxidant, and continue to stir for 30 - 40 min; obtain a transparent high-impact heat-resistant MBS resin through demulsification, centrifugation, washing and drying.

[0027] Compared with the prior art, the beneficial effects obtained by the present invention:

[0028] (1) The thermal decomposition temperature of the transparent high-impact heat-resistant MBS resin prepared by the present invention is as high as above 240 °C.

[0029] (2) The transparent, high-impact and heat-resistant MBS resin prepared by the present invention can significantly improve the cantilever beam impact strength and aging resistance of PVC materials.

[0030] (3) The PVC material modified with the transparent, high-impact and heat-resistant MBS resin of the present invention has a high light transmittance. Specific Embodiments

[0031] The following preferred embodiments of the present invention are only used to explain and illustrate the present invention, and are not used to limit the present invention.

[0032] Example 1 Preparation Method of a Transparent, High-Impact and Heat-Resistant MBS Resin

[0033] Step 1. Pre-emulsification

[0034] Add distilled water and sodium dodecyl sulfate into the reaction kettle in sequence, stir at room temperature at a rotation speed of 300 r / min until transparent; introduce nitrogen to displace the air in the reaction kettle, add butadiene and styrene, and continue stirring for 25 min to obtain a pre-emulsion.

[0035] The feeding mass ratio of the distilled water, sodium dodecyl sulfate, butadiene and styrene is 100:3:15:8.

[0036] Step 2. Gradient Crosslinking and Synthesis of Modified Styrene-Butadiene Latex

[0037] Divide the pre-emulsion into two parts, and the mass ratio of the first part of the pre-emulsion to the second part of the pre-emulsion is 1:2; divide divinylbenzene into 4 equal parts;

[0038] Add the first part of the pre-emulsion into the reaction kettle, introduce nitrogen to displace the air in the reaction kettle, heat the reaction system to 75 °C, and start stirring at a stirring rate of 250 r / min. Add glycidyl methacrylate, ammonium persulfate and one part of divinylbenzene, and stir and react at a constant temperature for 3 h; then continuously add the second part of the pre-emulsion below the liquid level in the kettle, and the feeding time is 2 h. Among them, 40 min after adding the second part of the pre-emulsion, start to add the remaining divinylbenzene in three times, add it once every 30 min, and add one part of divinylbenzene each time. After adding, react for 40 min; heat the reaction system to 80 °C, add potassium persulfate, and stir and react for 4 h; centrifuge to obtain the modified styrene-butadiene latex for standby; the particle size distribution measured by a dynamic light scattering instrument is 148 ± 8 nm.

[0039] The feeding mass ratio of the pre-emulsion, glycidyl methacrylate, ammonium persulfate, divinylbenzene and potassium persulfate is 100:7:0.3:4:0.8.

[0040] Step 3. Grafting and Synthesis of MBS Resin Latex

[0041] Potassium persulfate and methyl methacrylate are mixed in a mass ratio of 1.0:20 to obtain a mixed solution A.

[0042] Methyl methacrylate and styrene are mixed in a mass ratio of 80:65 to obtain a mixed solution B.

[0043] The mass ratio of methyl methacrylate in the above-mentioned mixed solution A and mixed solution B is 1:3.

[0044] Distilled water, modified styrene-butadiene latex and sodium bisulfite are successively added to the reaction kettle, and the air in the reaction kettle is replaced with nitrogen. Stirring is carried out at a rate of 350 r / min. When the temperature of the reaction kettle rises to 70 °C and the reaction lasts for 12 min, the mixed solution A is added and stirred evenly. The mixed solution B is added dropwise through a peristaltic pump for 2.5 h, and constant-temperature stirring reaction is carried out; MBS resin grafted latex is obtained.

[0045] The feeding mass ratio of the distilled water, modified styrene-butadiene latex, sodium bisulfite, potassium persulfate, methyl methacrylate and styrene is 350:90:1.2:1.0:100:65.

[0046] Step 4, Heat-resistant monomer modified grafted shell

[0047] Ethanol, maleic anhydride and sodium dodecyl sulfate are ultrasonically dispersed for 5 min, and then distilled water is added and ultrasonically dispersed for another 10 min to form a uniform maleic anhydride emulsion for standby; the MBS resin latex is added to the reaction kettle, and the stirring rate is set at 400 r / min; the maleic anhydride emulsion is added dropwise through a peristaltic pump, and the dropping time is 1 h; after the dropping is completed, the air in the reaction kettle is replaced with nitrogen, the reaction system is heated to 80 °C, potassium persulfate is added, and constant-temperature stirring reaction is carried out for 4 h; the reaction system is cooled to 45 °C, vitamin E and tris(nonylphenyl) phosphite are added, and stirring is continued for 30 min; through demulsification, centrifugation, washing and drying, a transparent high-impact heat-resistant MBS resin is obtained.

[0048] The mass ratio of the distilled water, ethanol, maleic anhydride, sodium dodecyl sulfate, MBS resin grafted latex, potassium persulfate, vitamin E and tris(nonylphenyl) phosphite is 300:30:20:5:100:1.5:1.0:0.5.

[0049] Example 2 Preparation method of a transparent high-impact heat-resistant MBS resin

[0050] Step 1, Pre-emulsification

[0051] Add distilled water and sodium dodecylbenzenesulfonate into the reaction kettle in sequence, stir at room temperature at a speed of 250 r / min until it becomes transparent; introduce nitrogen to displace the air in the reaction kettle, add butadiene and styrene, and continue stirring for 30 min to obtain a pre-emulsion.

[0052] The feeding mass ratio of the distilled water, sodium dodecyl sulfate, butadiene and styrene is 100:1.5:12:12.

[0053] Step 2: Gradient cross-linking synthesis of modified styrene-butadiene latex

[0054] Divide the pre-emulsion into two parts, and the mass ratio of the first part of the pre-emulsion to the second part of the pre-emulsion is 1:3; divide divinylbenzene into 6 equal parts;

[0055] Add the first part of the pre-emulsion into the reaction kettle, introduce nitrogen to displace the air in the reaction kettle, heat the reaction system to 65 °C, and start stirring at a stirring rate of 350 r / min. Add glycidyl methacrylate, ammonium persulfate and one part of divinylbenzene, and stir and react at a constant temperature for 2 h; then continuously add the second part of the pre-emulsion below the liquid level in the kettle, and the feeding time is 3 h. Among them, 30 min after adding the second part of the pre-emulsion, start to add the remaining divinylbenzene in five equal portions, add once every 20 min, add one part of divinylbenzene each time. After the addition is completed, react for 30 min; heat the reaction system to 85 °C, add potassium persulfate, and stir and react for 2.5 h; centrifuge to obtain modified styrene-butadiene latex for standby; its particle size distribution measured by a dynamic light scattering instrument is 153±12 nm.

[0056] The feeding mass ratio of the pre-emulsion, glycidyl methacrylate, ammonium persulfate, divinylbenzene and potassium persulfate is 100:10:0.2:6:0.5.

[0057] Step 3: Graft synthesis of MBS resin latex

[0058] Mix potassium persulfate and methyl methacrylate according to a mass ratio of 1.0:20 to obtain mixture A.

[0059] Mix methyl methacrylate and styrene according to a mass ratio of 80:70 to obtain mixture B.

[0060] Add distilled water, modified styrene-butadiene latex and sodium bisulfite into the reaction kettle in sequence, use nitrogen to displace the air in the reaction kettle, stir at a rate of 300 r / min, raise the temperature of the reaction kettle to 75 °C, after reacting for 8 min, add mixture A, stir evenly, and dropwise add mixture B through a peristaltic pump for 2 h, and carry out constant temperature stirring reaction; obtain MBS resin grafted latex.

[0061] The feeding mass ratio of the distilled water, modified styrene-butadiene latex, sodium bisulfite, potassium persulfate, methyl methacrylate and styrene is 400:100:0.7:1.0:100:70.

[0062] Step 4, heat-resistant monomer modified grafted shell

[0063] Ultrasonically disperse ethanol, maleic anhydride and sodium dodecylbenzenesulfonate for 7 min, add distilled water and then ultrasonically disperse for another 30 min to form a uniform maleic anhydride emulsion for standby; add the MBS resin latex into the reaction kettle, and set the stirring rate to 300 r / min; drip the maleic anhydride emulsion with a peristaltic pump, and the dripping time is 2 h; after the dripping is completed, displace the air in the reaction kettle with nitrogen, heat up the reaction system to 70 °C, add potassium persulfate, and stir and react at a constant temperature for 2 h; cool down the reaction system to 35 °C, add vitamin E and pentaerythritol tetra(β-(3,5 - di-tert-butyl - 4 - hydroxyphenyl)propionate), and continue stirring for 40 min; obtain a transparent high impact-resistant heat-resistant MBS resin through demulsification, centrifugation, washing and drying.

[0064] The mass ratio of the distilled water, ethanol, maleic anhydride, sodium dodecylbenzenesulfonate, MBS resin grafted latex, potassium persulfate, vitamin E and pentaerythritol tetra(β-(3,5 - di-tert-butyl - 4 - hydroxyphenyl)propionate) is 400:30:25:8:100:1.0:1.0:1.0.

[0065] Example 3 Preparation method of a transparent high impact-resistant heat-resistant MBS resin

[0066] Step 1, pre-emulsification

[0067] Add distilled water and sodium dodecyl sulfate into the reaction kettle in sequence, carry out normal temperature stirring at a speed of 350 r / min until it is transparent; displace the air in the reaction kettle with nitrogen, add butadiene and styrene, and continue stirring for 35 min to obtain a pre-emulsion.

[0068] The feeding mass ratio of the distilled water, sodium dodecyl sulfate, butadiene and styrene is 100:2.5:18:10.

[0069] Step 2, gradient crosslinking synthesis of modified styrene-butadiene latex

[0070] Divide the pre-emulsion into two parts, and the mass ratio of the first part of the pre-emulsion to the second part of the pre-emulsion is 1:2; divide divinylbenzene into 5 equal parts;

[0071] Add the first portion of the pre-emulsion into the reaction kettle, introduce nitrogen to displace the air in the reaction kettle, heat the reaction system to 70 °C, and start stirring at a stirring rate of 300 r / min. Add glycidyl methacrylate, ammonium persulfate, and one portion of divinylbenzene, and stir the reaction at a constant temperature for 2.5 h; then continuously feed the second portion of the pre-emulsion below the liquid level in the kettle, and the feeding time is 2.5 h. Among them, 35 min after adding the second portion of the pre-emulsion, start to add the remaining divinylbenzene in four portions, add once every 25 min, add one portion of divinylbenzene each time, and react for 35 min after adding; heat the reaction system to 82 °C, add potassium persulfate, and stir the reaction for 3 h; centrifuge to obtain the modified styrene-butadiene latex for standby; the particle size distribution measured by the dynamic light scattering instrument is 158 ± 18 nm.

[0072] The feeding mass ratio of the pre-emulsion, glycidyl methacrylate, ammonium persulfate, divinylbenzene, and potassium persulfate is 100:5:0.5:5:0.3.

[0073] Step 3, graft copolymerize the MBS resin latex

[0074] Mix potassium persulfate and methyl methacrylate according to a mass ratio of 0.5:20 to obtain mixture A.

[0075] Mix methyl methacrylate and styrene according to a mass ratio of 80:60 to obtain mixture B.

[0076] The mass ratio of methyl methacrylate in the above mixture A and mixture B is 1:3.

[0077] Add distilled water, modified styrene-butadiene latex, and sodium bisulfite into the reaction kettle in sequence, use nitrogen to displace the air in the reaction kettle, stir at a rate of 250 r / min, raise the temperature of the reaction kettle to 80 °C, after reacting for 10 min, add mixture A, stir evenly, and dropwise add mixture B through a peristaltic pump for 2 h, and carry out stirring reaction at a constant temperature; obtain the MBS resin grafted latex.

[0078] The feeding mass ratio of the distilled water, modified styrene-butadiene latex, sodium bisulfite, potassium persulfate, methyl methacrylate, and styrene is 300:80:0.3:0.5:100:60.

[0079] Step 4, modify the grafted shell layer with heat-resistant monomers

[0080] Ethanol, maleic anhydride, and sodium dodecylbenzenesulfonate were ultrasonically dispersed for 10 min, and then distilled water was added followed by another 25 min of ultrasonic dispersion to form a uniform maleic anhydride emulsion for standby. The MBS resin latex was added to a reaction kettle, and the stirring rate was set at 400 r / min. The maleic anhydride emulsion was added dropwise using a peristaltic pump over a period of 1.5 h. After the addition was completed, the air in the reaction kettle was replaced with nitrogen, the reaction system was heated to 75 °C, potassium persulfate was added, and the mixture was stirred at a constant temperature for 3 h. The reaction system was cooled to 40 °C, tris(nonylphenyl) phosphite and n-octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate were added, and stirring was continued for 35 min. A transparent high-impact heat-resistant MBS resin was obtained through demulsification, centrifugation, washing, and drying.

[0081] The mass ratio of the distilled water, ethanol, maleic anhydride, sodium dodecylbenzenesulfonate, MBS resin graft latex, potassium persulfate, tris(nonylphenyl) phosphite, and n-octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate is 350:40:35:10:100:1.5:0.5:1.0.

[0082] Comparative Example 1 A method for preparing an MBS resin

[0083] Step 1. Pre-emulsification

[0084] It is the same as Step 1 of Example 1.

[0085] Step 2. Synthesis of styrene-butadiene latex

[0086] Compared with Step 2 of Example 1, glycidyl methacrylate was not added, and the pre-emulsion and cross-linking agent were fed in one batch. The particle size distribution measured by a dynamic light scattering instrument was 275 ± 45 nm.

[0087] Step 3. Graft synthesis of MBS resin latex

[0088] Compared with Step 3 of Example 1, the modified styrene-butadiene latex was replaced with the styrene-butadiene latex synthesized in Step 2.

[0089] Example 4 Performance testing

[0090] (I) Thermal decomposition temperature test

[0091] The MBS resins produced in Examples 1-3 and Comparative Example 1 were respectively cryogenically frozen in liquid nitrogen and subjected to the following treatment: The rotation speed of the cryogenic ball mill was set at 200 r / min, and grinding was carried out for 10 min. Uniform powder passing through a 100-mesh sieve was collected as a sample.

[0092] The thermal decomposition temperature of the samples was tested according to "Plastics - Determination of decomposition temperature by thermogravimetry (TGA) (GB / T 27761-2011)". The specific results are shown in Table 1.

[0093] Table 1 Test results of thermal decomposition temperature

[0094] From the data in Table 1, it can be known that the thermal decomposition temperature of the transparent high - impact heat - resistant MBS resin prepared in Examples 1 - 3 of the present invention reaches 243 - 258 °C, significantly improving the heat - resistant performance of the MBS resin.

[0095] Determination of light transmittance and haze

[0096] The MBS resins prepared in Examples 1 - 3 and Comparative Example 1 were respectively made into samples. The preparation method was as follows:

[0097] The MBS resin and PVC were mixed in a mass ratio of 1:9, and introduced into a twin - screw extruder for melt blending at 180 °C, and then pressed into a thin sheet with a thickness of 1.0 ± 0.05 mm by a flat vulcanizing machine, and cut into circular samples with a diameter of 50 mm.

[0098] The light transmittance and haze of the samples were tested according to "Determination of light transmittance and haze of transparent plastics (GB / T 2410-2008)". The specific results are shown in Table 2.

[0099] Table 2 Test results of light transmittance and haze

[0100] From the data in Table 2, it can be known that the light transmittance of the PVC composite material modified by the transparent high - impact heat - resistant MBS resin prepared in the present invention reaches 88 - 90.5%, and the haze reaches 2.8 - 4.2%; compared with Comparative Example 1, the light transmittance of the PVC composite material modified in the present invention has been significantly improved, and the haze has been greatly reduced.

[0101] (3) Cantilever beam impact strength test

[0102] The MBS resins prepared in Examples 1 - 3 and Comparative Example 1 were respectively made into samples. The preparation method was as follows:

[0103] The MBS resin, PVC, organotin stabilizer and lubricant HLD - 74 were mixed evenly in a mass ratio of 1:10:0.2:0.3, and injection - molded under the injection - molding conditions of 180 °C and 5 Mpa. After holding pressure for 5 s, cooling and demolding were carried out to obtain impact bars with dimensions of 80 × 10 × 4 mm. Then, a notch with a width of 2.0 mm ± 0.2 mm was machined at the center of the width direction of the impact bar with a Type A notch tool to make test samples.

[0104] The Izod impact strength of the samples was tested according to "Plastics - Determination of Izod impact strength - Part 1: Non-instrumented impact test (GB / T 1843-2008)", and the specific results are shown in Table 3.

[0105] Table 3 Test results of Izod impact strength

[0106] According to the data in Table 3, it can be known that the transparent high-impact heat-resistant PVC composite modified by the MBS resin prepared in the present invention has an Izod impact strength of 18.1 - 21.3 kJ / m²; compared with Comparative Example 1, the Izod impact strength of the PVC composite modified in the present invention has been significantly improved.

[0107] (4) Aging resistance test

[0108] The MBS resins prepared in Examples 1 - 3 and Comparative Example 1 were respectively made into samples, and the preparation method was as follows:

[0109] The MBS resin, PVC, organotin stabilizer and lubricant HLD-74 were mixed evenly according to a mass ratio of 1:10:0.2:0.3, introduced into a two-roll mill for melt blending at 180 °C, and then pressed into a thin sheet with a thickness of 0.5 ± 0.05 mm by a flat vulcanizing machine, and cut into square samples of 20 × 20 mm.

[0110] The aging resistance of the samples was tested according to "Plastics - Determination of yellowness index and its change (GB / T 39822-2021)", and the specific results are shown in Table 4.

[0111] Table 4 Test results of aging resistance

[0112] According to the data in Table 4, it can be known that the transparent high-impact heat-resistant PVC composite modified by the MBS resin prepared in the present invention has good aging resistance, the yellowness index is 3.2 - 4.2, and the yellowness index is significantly reduced.

[0113] From the test data, it can be known that the present invention not only reduces the temperature limit of MBS application, but also the transparent high-impact heat-resistant MBS resin prepared in the present invention can significantly improve the properties such as light transmittance, Izod impact strength, haze and aging resistance of PVC materials.

[0114] The above is only the preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. A transparent high-impact heat-resistant MBS resin, characterized in that: It is prepared from the following raw materials: water, ethanol, maleic anhydride, emulsifier, MBS resin graft latex, potassium persulfate, antioxidant; The MBS resin graft latex is prepared from the following raw materials: water, modified styrene-butadiene latex, sodium bisulfite, potassium persulfate, methyl methacrylate and styrene, and the mass ratio is (300 - 400):(80 - 100):(0.3 - 1.2):(0.5 - 1.0):100:(60 - 70); The modified styrene-butadiene latex is prepared from the following raw materials: pre-emulsion, glycidyl methacrylate, ammonium persulfate, divinylbenzene, potassium persulfate, and the mass ratio is 100:(5 - 10):(0.2 - 0.5):(4 - 6):(0.3 - 0.8); The pre-emulsion is prepared from the following raw materials: water, emulsifier, butadiene and styrene; The preparation method of the transparent high-impact heat-resistant MBS resin includes steps of pre-emulsification, gradient cross-linking synthesis of modified styrene-butadiene latex, graft synthesis of MBS resin latex, and heat-resistant monomer modified graft shell layer; For the gradient cross-linking synthesis of modified styrene-butadiene latex: divide the pre-emulsion into two parts, and the mass ratio of the first part of pre-emulsion to the second part of pre-emulsion is 1:(2 - 3); divide divinylbenzene into 4 - 6 equal parts; React the first part of pre-emulsion with glycidyl methacrylate, ammonium persulfate and 1 part of divinylbenzene at 65 - 75 °C for 2 - 3 h; add the second part of pre-emulsion, and the feeding time is 2 - 3 h; add the remaining divinylbenzene in portions, add 1 part of divinylbenzene every 20 - 30 min, and react for 30 - 40 min after adding; raise the temperature of the reaction system to 80 - 85 °C, add potassium persulfate, and react for 2.5 - 4 h; The heat-resistant monomer modified graft shell layer: Stir the MBS resin latex, and dropwise add the pre-emulsified maleic anhydride emulsion; under the protection of inert gas, raise the temperature of the reaction system to 70 - 80 °C, add potassium persulfate, and react for 2 - 4 h; add antioxidant, and continue to stir for 30 - 40 min; obtain the transparent high-impact heat-resistant MBS resin through demulsification, centrifugation, washing and drying.

2. A transparent high-impact heat-resistant MBS resin according to claim 1, characterized in that: The mass ratio of the water, ethanol, maleic anhydride, emulsifier, MBS resin graft latex, potassium persulfate, antioxidant is (300 - 400):(30 - 40):(25 - 35):(5 - 10):100:(1.0 - 1.5):(1.0 - 2.0).

3. A transparent high-impact heat-resistant MBS resin according to claim 1, characterized in that: The raw materials of the pre-emulsion: the mass ratio of water, emulsifier, butadiene and styrene is 100:(1.5 - 3.0):(12 - 18):(8 - 12).

4. A transparent high impact heat resistant MBS resin according to claim 1, characterized in that: The antioxidant is any two of vitamin E, tris(nonylphenyl) phosphite, n-octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate).

5. A transparent high-impact heat-resistant MBS resin according to claim 1, characterized in that: The emulsifier is any one of sodium dodecyl sulfate and sodium dodecylbenzenesulfonate.

6. A transparent high-impact heat-resistant MBS resin according to claim 1, wherein: The graft copolymerized MBS resin latex: Potassium persulfate and methyl methacrylate are mixed in a mass ratio of (0.5 - 1.0):20 to obtain a mixed solution A; Methyl methacrylate and styrene are mixed in a mass ratio of 80:(60 - 70) to obtain a mixed solution B; Water, modified styrene-butadiene latex and sodium bisulfite are mixed, and after reacting at 70 - 80 °C for 8 - 12 min, the mixed solution A is added; the mixed solution B is added dropwise, and the dropping time is 2 - 2.5 h; An MBS resin latex is obtained.

7. The heat-resistant MBS resin with high transparency and high impact resistance according to claim 1, characterized in that: The stirring rate of the stirring is 300 - 400 r / min.

8. A transparent high impact heat resistant MBS resin according to claim 1, characterized in that: The dropping time of the dropping is 1 - 2 h.

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