A sebs carrier silicone master batch and a preparation method thereof

Abstract

The application discloses a kind of SEBS carrier silicone master batch and preparation method thereof.The silicone master batch uses SEBS as carrier, the silicone used is modified dimethylsiloxane, and modified white carbon black is added, and is made into after high-temperature mixing using double screw extruder.The silicone master batch of the application uses SEBS as carrier, has excellent dispersibility and compatibility;Use modified dimethylsiloxane, reaction occurs in the mixing process, enhance its dispersibility and compatibility with SEBS;Add modified white carbon black to provide bonding site, enhance the compatibility of SEBS and dimethylsiloxane, improve the uniformity of dispersion.Use the silicone master batch of the application can greatly reduce die casting, and the strength of the extrusion, injection molding type TPE / TPR material prepared is high.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high polymer material functional additives, in particular to a SEBS carrier silicone master batch and a preparation method thereof. BACKGROUND

[0002] Thermoplastic elastomer is a new type of high polymer material between rubber and resin, which can not only replace part of rubber, but also modify plastic. The dual performance of rubber and plastic and wide characteristics of thermoplastic elastomer make it widely used in rubber industry to manufacture daily products such as rubber shoes, rubber cloth and various industrial products such as rubber pipes, rubber tapes, rubber strips, rubber plates, rubber parts and adhesives.

[0003] At present, the demand for extrusion and injection molding TPE / TPR materials is increasing at home and abroad. TPE / TPR materials are widely used in daily life, such as communication wire, elastomer pipe, sheet and the like. TPE materials include styrene, olefin, diene, vinyl chloride, urethane, ester, amide, organic fluorine, organic silicon and ethylene, which almost cover all fields of synthetic rubber and synthetic resin. However, due to the poor heat resistance of TPE compared with rubber, the physical properties decrease greatly with the increase of temperature, so the application range is limited. At the same time, the compression deformation, resilience and durability are poorer than rubber, and the price is also higher than that of the same kind of rubber. Therefore, it is often necessary to add additives such as compatibilizers and talc. However, due to the large filling amount of various additives, the processing performance of the high polymer matrix material is seriously affected, and the compatibility of each component in the system is reduced. With the increase of filling amount, the mold flow is easily formed due to the precipitation of fillers in the system and the friction between polymer melt and metal wall of the die. The extrusion expansion and melt rupture of polymer melt aggravate the formation of mold flow, which leads to frequent shutdown and cleaning during production and processing, affecting the production efficiency. Poor compatibility of the system will lead to rough surface of the finished product, affecting the smoothness of the finished product surface.

[0004] In view of the above mold flow problem, the existing technology usually improves by changing the process, such as improving the extrusion processing temperature of the material, air blowing at the outlet of the die and coating the die head, but the effect is not good. With the continuous development of processing aid technology, the existing technology also has a technical scheme of adding silicone master batch to TPE material to improve the mold flow.

[0005] However, the silicone master batch of the prior art has limited compatibility, dispersibility and affinity of low molecular weight polysiloxane and carrier resin polyolefin resin, so that the application of silicone master batch may affect the mechanical properties of resin finished product, and the mold flow problem still exists in the application process.

[0006] Therefore, there is a need for a silicone master batch which can greatly reduce die flow and has high strength of the prepared extrusion, injection type TPE / TPR material. SUMMARY

[0007] The present application aims at providing a SEBS carrier silicone master batch and a preparation method thereof to solve the problems of serious die flow when using the silicone master batch in the prior art and insufficient strength of the prepared extrusion, injection type TPE / TPR material.

[0008] TECHNICAL SOLUTION

[0009] A SEBS carrier silicone master batch comprises the following components in parts by weight:

[0010] SEBS 40-60 parts

[0011] Modified dimethylsiloxane 40-60 parts

[0012] Antioxidant 0.5-1.5 parts

[0013] Modified white carbon black 3-5 parts.

[0014] Further, the SEBS carrier silicone master batch comprises the following components in parts by weight:

[0015] SEBS 50-55 parts

[0016] Modified dimethylsiloxane 45-50 parts

[0017] Antioxidant 0.5-1.5 parts

[0018] Modified white carbon black 3-5 parts.

[0019] The present application finds a proportion range with high dispersion degree and compatibility between SEBS and modified dimethylsiloxane by adjusting the content ratio between SEBS and modified dimethylsiloxane through experiments, and the SEBS carrier silicone master batch prepared in the proportion range provided by the present application can greatly reduce die flow and has high strength of the prepared extrusion, injection type TPE / TPR material.

[0020] The silicone master batch provided by the present application takes SEBS as a carrier, and SEBS thermoplastic elastomer is a new type of high molecular material between rubber and resin, which can have the dual performance of rubber and plastic and wide properties. Therefore, SEBS has good dissolving performance, blending performance and excellent oiling performance, can be dissolved in many common solvents, and has a solubility parameter of 7.2-9.6, and has high compatibility with modified dimethylsiloxane.

[0021] Further, the SEBS has a polystyrene content of 30-50% by weight and a rubber phase content of 50-70% by weight.

[0022] The SEBS resin used in the application defines the content ratio of polystyrene and rubber phase, so that it has stronger dispersion capacity and compatibility.

[0023] Further, the SEBS is a linear or star-shaped structure polymer with a number average molecular weight of 1-1.2 million.

[0024] The application limits the number average molecular weight of SEBS so that it has better compatibility, affinity and dispersion.

[0025] Further, the modified dimethylsiloxane is selected from one of hydroxyl-terminated dimethylsiloxane, carboxyl-polydimethylsiloxane or amino-terminated polydimethylsiloxane; and the modified dimethylsiloxane has a viscosity of 50,000±5,000 mPa·s.

[0026] The modified dimethylsiloxane has better compatibility with SEBS, and the dispersion of the two is more uniform, and the modified dimethylsiloxane can react with SEBS, further improving the performance and dispersion of the material.

[0027] The use of dimethylsiloxane with higher viscosity can make the prepared extrusion and injection molding TPE / TPR material have better elongation and strength.

[0028] Further, the modified white carbon black is prepared by the following steps:

[0029] (1) dispersing the white carbon black in an aqueous ethanol solution, adjusting the pH value to 3-4 using an acetic acid solution, then adding MP-200 silane coupling agent, and reacting at 60-65°C for 4-6 hours;

[0030] (2) after the reaction is completed, the obtained suspension is cooled to room temperature, centrifuged and washed, and then dried in a drying oven at 75-80°C for 20-24 hours to obtain modified white carbon black.

[0031] The application adds fumed white carbon black, which has a large specific surface area, can provide bonding sites for SEBS and dimethylsiloxane, enhance the compatibility of the two, and improve the uniformity of dispersion. However, due to the large amount of hydroxyl groups on the surface of the white carbon black, agglomeration easily occurs and the white carbon black cannot be uniformly dispersed in the master batch, so the white carbon black is modified in the application.

[0032] The present application modifies the white carbon black by MP-200 silane coupling agent, reduces the exposure of the surface hydroxyl group of the white carbon black, improves the lipophilicity of the surface, and inhibits the agglomeration behavior of the white carbon black in SEBS; the silane coupling agent used in the present application is MP-200, which is a bifunctional organic silane with an epoxy group and a hydrolyzable inorganic methoxy silicon group, which can not only consume the surface hydroxyl group of the white carbon black but also further enhance the adhesion of the white carbon black, so that the SEBS and dimethylsiloxane are organically bonded together.

[0033] Further, the auxiliary agent is selected from one of antioxidant 1010, antioxidant 1076, antioxidant 168 or DLTP.

[0034] The addition of the antioxidant in the blending process can enhance the stability of the reaction, reduce the occurrence of side reactions, and can enhance the antioxidant capacity of the prepared silicone masterbatch.

[0035] The preparation method of the SEBS carrier silicone masterbatch comprises the following steps:

[0036] (1) adding SEBS, modified dimethylsiloxane, antioxidant and modified white carbon black into a pressurized internal mixer for melt mixing;

[0037] (2) transferring the mixed material in step (1) to a twin-screw extruder for extrusion granulation to prepare the SEBS carrier silicone masterbatch.

[0038] Further, the mixing temperature in step (1) is 200-220 DEG C; and the time is 10-20 minutes.

[0039] Further, in step (2), the screw feeding section temperature of the extruder is 190-200 DEG C, the conveying section temperature is 200-205 DEG C, the melting section temperature is 210-220 DEG C, the die temperature is 210-215 DEG C, and the screw rotation speed is 200-240 r / min.

[0040] SEBS has excellent thermal stability and shear degradation resistance, and the melt is easy to shape, the embrittlement temperature is less than -60 DEG C, and the use temperature can reach 149 DEG C. In an oxygen atmosphere, the decomposition temperature is greater than 270 DEG C, so the present application uses a higher temperature in the preparation process, so that the dispersion and compatibility of SEBS and dimethylsiloxane in the prepared silicone masterbatch are more sufficient and uniform.

[0041] The raw materials are sheared and fused in a twin-screw extruder, so that SEBS and dimethylsiloxane are fully plasticized and fused under high temperature and high-speed shearing action of the screw, fully contact with each other, so that the hydroxyl and carboxyl groups of the two react under the action of heat to form a certain degree of connector, which can increase the dispersion and compatibility of the two.

[0042] Advantages:

[0043] (1) The silicone master batch provided by the application takes SEBS as a carrier, and based on its double performance of rubber and plastic and wide nature, it can be fully compatible and dispersed with dimethyl polysiloxane, so that the prepared silicone master batch can greatly reduce die flow, and the prepared extrusion and injection type TPE / TPR material has high strength.

[0044] (2) The silicone master batch provided by the application uses modified dimethyl siloxane, and the hydroxyl, carboxyl or amino group is used for substitution, and the active group is used for reaction with SEBS during extrusion granulation, so that the dispersion and compatibility of SEBS and dimethyl siloxane in the prepared silicone master batch are more sufficient and uniform.

[0045] (3) The silicone master batch provided by the application adjusts the content ratio between the SEBS carrier and dimethyl siloxane, so that the compatibility and dispersion degree of the two can reach a high level, so that the prepared SEBS carrier silicone master batch can greatly reduce die flow, and the prepared extrusion and injection type TPE / TPR material has high strength.

[0046] (4) The preparation method of the silicone master batch provided by the application controls the temperature and time of the extrusion granulation process based on the thermal stability of SEBS and modified dimethyl siloxane, so that the two are fully plasticized and fused, and the silicone master batch with high compatibility and dispersion is prepared; and based on the esterification reaction of the carboxyl and hydroxyl groups under the action of heat, the silicone master batch of the application can have higher elongation at break and tensile strength when used for preparing extrusion and injection type TPE / TPR materials.

[0047] (5) The silicone master batch provided by the application enhances the compatibility of the two and improves the uniformity of dispersion by adding modified white carbon black; the white carbon black is modified by the MP-200 silane coupling agent in the application, the exposure of the hydroxyl group on the surface of the white carbon black is reduced, the lipophilicity of the surface is improved, and the agglomeration behavior of the white carbon black in SEBS is inhibited; the silane coupling agent used in the application is MP-200, which is an organic silane with an epoxy group and a hydrolyzable inorganic methoxy silicon group double functional group, which can not only consume the hydroxyl group on the surface of the white carbon black but also further enhance the adhesion of the white carbon black, so that SEBS and dimethyl siloxane can be organically bonded together. DETAILED DESCRIPTION

[0048] The application will be described below in conjunction with specific embodiments. It should be noted that the following examples are examples of the application and are only used to illustrate the application, but not to limit the application. Other combinations and various modifications within the concept of the application can be made without departing from the main idea or scope of the application.

[0049] Common silicone masterbatch-1 and common silicone masterbatch-2 are YZ-2 and SPP purchased from Dongguan Yaozhong Trade Co., Ltd., respectively; carboxyl-polydimethylsiloxane is purchased from Xi'an Qiyue Biological Technology Co., Ltd.; amino-terminated polydimethylsiloxane is purchased from Shanghai Dingfen Chemical Technology Co., Ltd.; MP-200 silane coupling agent is purchased from Shanghai Sangjing Chemical Co., Ltd.; common white carbon black is gas rubber method white carbon black purchased from Guangzhou Liben Rubber Raw Materials Trade Co., Ltd. The remaining reagents and equipment are conventional reagents and equipment in the technical field.

[0050] Preparation of modified white carbon black

[0051] (1) 100 g of white carbon black was dispersed in 1000 mL of 95% (by volume) ethanol aqueous solution, and the pH value was adjusted to 3-4 using acetic acid solution, then 15 g of MP-200 silane coupling agent was added, and reacted at 60°C for 4 hours.

[0052] (2) After the reaction was completed, the obtained suspension was cooled to room temperature, separated by centrifugation and washed with anhydrous ethanol for 3 times to remove unreacted coupling agent, acetic acid, etc., and dried in a drying oven at 80°C for 24 hours to obtain modified white carbon black.

[0053] Example 1

[0054] The SEBS carrier silicone masterbatch was prepared according to the following steps:

[0055] (1) SEBS, hydroxyl-terminated dimethylsiloxane, antioxidant 1010 and modified white carbon black were added to a pressurized internal mixer for melt mixing, and the mixing temperature was 220°C, and the time was 20 minutes;

[0056] (2) The mixed material in step (1) was transferred to a twin-screw extruder for extrusion granulation to obtain the SEBS carrier silicone masterbatch, and the screw feeding section temperature of the extruder was 200°C, the conveying section temperature was 205°C, the melting section temperature was 220°C, the die head temperature was 215°C, and the screw rotation speed was 240 r / min.

[0057] The weight fractions of the components are as follows:

[0058] SEBS 40 parts

[0059] Hydroxyl-terminated dimethylsiloxane 59 parts

[0060] Antioxidant 1010 1 part

[0061] Modified white carbon black 5 parts.

[0062] Example 2

[0063] The same as example 1, except that the weight fraction of SEBS is changed to 45 parts, and the weight fraction of the hydroxyl-terminated dimethyl siloxane is changed to 54 parts of carboxyl-polydimethyl siloxane.

[0064] Example 3

[0065] The same as example 1, except that the weight fraction of SEBS is changed to 50 parts, and the weight fraction of the hydroxyl-terminated dimethyl siloxane is changed to 49 parts of amino-terminated polydimethyl siloxane.

[0066] Example 4

[0067] The same as example 1, except that the weight fraction of SEBS is changed to 55 parts, and the weight fraction of the hydroxyl-terminated dimethyl siloxane is changed to 44 parts.

[0068] Example 5

[0069] The same as example 1, except that the weight fraction of SEBS is changed to 60 parts, and the weight fraction of the hydroxyl-terminated dimethyl siloxane is changed to 39 parts.

[0070] Comparative Example 1

[0071] The same as example 1, except that the weight fraction of SEBS is changed to 30 parts, and the weight fraction of the hydroxyl-terminated dimethyl siloxane is changed to 69 parts.

[0072] Comparative Example 2

[0073] The same as example 1, except that the weight fraction of SEBS is changed to 70 parts, and the weight fraction of the hydroxyl-terminated dimethyl siloxane is changed to 29 parts.

[0074] Comparative Example 3

[0075] The same as example 1, except that the SEBS is changed to a TPU material.

[0076] Comparative Example 4

[0077] The same as example 1, except that the hydroxyl-terminated dimethyl siloxane is changed to polydimethyl siloxane.

[0078] Comparative Example 5

[0079] The same as example 1, except that the modified white carbon black is changed to ordinary white carbon black.

[0080] Comparative Example 6

[0081] The same as example 1, except that the modified white carbon black is not added.

[0082] Comparative Example 7

[0083] Ordinary silicone masterbatch-1.

[0084] Comparative Example 8

[0085] Common silicone masterbatch-2.

[0086] Performance test

[0087] 1. Die flow test: PP 30 parts, SEBS 10 parts, white oil 30 parts, antioxidant 0.3 parts, and 2 parts of the silicone masterbatch prepared in any one of the above examples 1-5 and comparative examples 1-8 are added, and after being uniformly mixed, they are extruded and granulated by a screw extruder at 130-150°C to obtain an extrusion and injection type TPE material. The extrusion and injection type TPE material is extruded and drawn on a cable single screw, and the die flow during extrusion is recorded. The silicone masterbatch prepared in the examples and comparative examples is used as a blank control group.

[0088] 2. Mechanical property test: The extrusion and injection type TPE material particles prepared in the above die feeding test are dried in a vacuum drying box at 70-80°C for 2 hours, then molded into a sheet on a flat curing instrument, and cut into dumbbell-shaped samples using a cutter. The mechanical property test is carried out according to the provisions of GB / T10707-2007, and a universal testing machine is used to test the samples with a thickness of (1.0±0.1) mm, and the tensile speed is (250±10) mm / min.

[0089] 3. Precipitation test: Clean and dry white oil-absorbing paper is used to wipe the surface of the extrusion and injection type TPE material. If there are oil marks on the paper, it is judged as having precipitation, and if there are no oil marks, it is judged as having no precipitation.

[0090]

[0091]

[0092] According to the comparison of examples 1-5 and comparative examples 7 and 8, the SEBS carrier silicone masterbatch provided by the application can greatly reduce die flow and oil precipitation when preparing an extrusion and injection type TPE material compared with the silicone masterbatch in the prior art; and the elongation at break and tensile strength of the extrusion and injection type TPE material prepared using the silicone masterbatch of the application are greatly improved.

[0093] According to the comparison of examples 1-5 and comparative examples 1 and 2, in the preparation of the SEBS carrier silicone masterbatch provided by the application, the content ratio of SEBS and dimethylsiloxane within the range provided by the application has excellent dispersity and compatibility, and too high or too low ratio of the two will affect the dispersity and compatibility, thereby affecting the degree of die flow and the quality of the TPE material.

[0094] According to the comparison of the embodiments 1-5 and the comparative example 3, it can be seen that the SEBS carrier silicone master batch provided by the application uses the carrier SEBS which has stronger dispersibility and compatibility compared with other carriers, and can be well dispersed and compatible with dimethylsiloxane, so that the silicone master batch prepared by the carrier has the effect of greatly reducing the die flow and oil and fat precipitation, and the performance of the extrusion and injection type TPE material prepared is stronger.

[0095] According to the comparison of the embodiments 1-5 and the comparative example 4, it can be seen that the dimethylsiloxane used in the SEBS carrier silicone master batch provided by the application is modified dimethylsiloxane, and the active groups thereof react with SEBS during the extrusion granulation, so that the dispersion and compatibility of SEBS and dimethylsiloxane in the prepared silicone master batch are more sufficient and uniform.

[0096] According to the comparison of the embodiments 1-5 and the comparative examples 5 and 6, it can be seen that the modified white carbon black used in the SEBS carrier silicone master batch provided by the application can enhance the compatibility and improve the uniformity of dispersion of the two; the use of the modified white carbon black can make SEBS and dimethylsiloxane organically bonded together, and enhance the dispersibility and compatibility.

[0097] The above embodiments are only for illustrating the technical concept and characteristics of the application, and the purpose is to enable those skilled in the art to understand the content of the application and implement it, and cannot limit the protection scope of the application, and any equivalent changes or modifications made according to the spirit and essence of the application should be covered within the protection scope of the application.

Claims

1. A SEBS-supported silicone masterbatch, characterized in that, The components comprise the following parts by weight: SEBS 40-60 copies 40-60 parts of modified dimethylsiloxane Antioxidant 0.5-1.5 parts 3-5 parts modified silica; The modified dimethylsiloxane is a hydroxyl-terminated dimethylsiloxane; the viscosity of the modified dimethylsiloxane is 50000±5000 mPa·s; The modified silica is prepared by the following steps: (1) Disperse silica in an aqueous ethanol solution and adjust the pH to 3-4 using acetic acid solution. Then add MP-200 silane coupling agent and react at 60-65℃ for 4-6 hours. (2) After the reaction is complete, the obtained suspension is cooled to room temperature, centrifuged, washed and dried in a drying oven at 75-80℃ for 20-24 hours to obtain modified silica.

2. The SEBS-supported silicone masterbatch according to claim 1, characterized in that, The components comprise the following parts by weight: SEBS 50-55 copies 45-50 parts of modified dimethylsiloxane Antioxidant 0.5-1.5 parts 3-5 parts modified silica.

3. The SEBS-supported silicone masterbatch according to claim 1, characterized in that, The SEBS contains 30-50% polystyrene by weight and 50-70% rubber phase by weight.

4. The SEBS-supported silicone masterbatch according to claim 1, characterized in that, The SEBS is a linear or star-shaped polymer with a number-average molecular weight of 1-1.2 million.

5. The SEBS-supported silicone masterbatch according to claim 1, characterized in that, The antioxidant is selected from one of antioxidant 1010, antioxidant 1076, antioxidant 168 or DLTP.

6. The method for preparing SEBS-supported silicone masterbatch according to any one of claims 1-5, characterized in that, Includes the following steps: (1) SEBS, modified dimethylsiloxane, antioxidant and modified silica are added to a pressure mixer for melt mixing; (2) Transfer the mixed material from step (1) to a twin-screw extruder for extrusion granulation to obtain the SEBS carrier silicone masterbatch.

7. The method for preparing SEBS-supported silicone masterbatch according to claim 6, characterized in that, In step (1), the mixing temperature is 200-220℃ and the time is 10-20 minutes.

8. The method for preparing SEBS-supported silicone masterbatch according to claim 6, characterized in that, In step (2), the temperature of the screw feeding section of the extruder is 190-200℃, the temperature of the conveying section is 200-205℃, the temperature of the melting section is 210-220℃, the temperature of the die head is 210-215℃, and the screw speed is 200-240r / min.

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