Continuous manufacturing process for rubber masterbatch and rubber masterbatch prepared therefrom

Abstract

The present invention relates to a continuous manufacturing process for a rubber masterbatch and a rubber masterbatch prepared therefrom. The manufacturing process comprises the following steps: step 1): a filler is added to a rubber solution, forming a rubber/filler/solvent mixture by stirring; and step 2): the solvent is removed and the mixture is dried, resulting in a rubber/filler masterbatch. The present invention also relates to a masterbatch prepared by the above-mentioned process and a rubber article prepared using the masterbatch. Compared to the wet mixing technologies in the prior art, the present invention has no specific requirements of rubber and filler, with a wider scope of usage. In addition, the filler has a high dispersion in rubber compounds, the production process thereof is continuous, highly efficient, low in energy consumption and labour, and thus low in cost.

Claims

1. A method for continuously producing a rubber masterbatch, comprising the following consecutive steps: step (1): adding a filler in a rubber solution, and stirring to form a rubber/filler/solvent mixture; step (2): removing the solvent, and drying said mixture to obtain a rubber/filler masterbatch; wherein, said drying in step 2) is that the mixture obtained in step 1) is transferred to a heating conveyor belt dryer, and heated and dried under vacuum or an inert gas, the volatilized solvent and the unreacted monomer in the synthesis of rubber enter into a condenser and a fractionation column for recovery; alternatively, said drying in step 2) is that the mixture obtained in step 1) is spray dried or flashed, and a heating medium used is an inert gas or water vapor, and the volatilized solvent and the unreacted monomer in the synthesis of rubber enter into the condenser and the fractionation column for recovering.

2. The method according to claim 1, wherein one or more additives selected from the group consisting of oil, an antioxidant, an anti-aging agent, a coupling agent, an active agent, a flame retardant, a heat stabilizer, a light stabilizer, a dye, a pigment, a vulcanizing agent, and an accelerating agent, are added in the step (1).

3. The method according to claim 1, wherein the step (1) comprises adding the filler into the rubber solution, stirring to form the rubber/filler/solvent mixture, as well as further finely and refinedly dispersing the rubber/filler/solvent mixture to improve the dispersity of the filler in the rubber solution.

4. The method according to claim 1, wherein the heating medium as described in the step (2) is water vapor, and the dried solid mixture contains water, and by vacuum drying, heat drying or extrusion heat drying, water is removed so as to obtain a rubber/filler masterbatch.

5. The method according to claim 4, wherein the heat drying is oven drying or air drying.

6. The method according to claim 4, wherein the extrusion heat drying comprises first extrusion to remove the heating medium, and then a further drying.

7. The method according to claim 6, wherein the further drying is air drying, oven drying or mechanical drying.

8. The method according to claim 7, wherein the mechanical drying is a drying by open mill, kneading machine, internal mixer, continuous internal mixer, single-screw extruder, or twin-screw extruder.

9. A rubber masterbatch prepared by the method according to claim 1.

10. A rubber article comprising the rubber masterbatch according to claim 9.

Description

DESCRIPTION OF THE PREFERRED EMBODIMENTS

(1) The present invention is further described by the examples blow, but the scope of the present invention is not limited to these examples.

(2) 1. The examples is determined by the following equipments and measuring methods:

(3) TABLE-US-00001 TABLE 1 Equipments for preparation of rubber samples Name of No. Equipment Specification/Model Manufacturer 1 Internal mixer XSM-1/10-120 Shanghai Kechuang Rubber machine Plastics Machinery Co., Ltd. 2 Open Mill 152.5*320 Guangdong Zhanjiang machinery Factory 3 Press XLB-D600*600 Zhejiang Huzhou Dongfang Vulcanizer Machinery Co., Ltd.

(4) TABLE-US-00002 TABLE 2 Methods and instruments for testing the physical properties of vulcanized rubber Test Name of Specification/ Manu- No. Test Item Standards Instruments Model facturer 1 Filler Carbon GT-505-CBD High Iron dispersion in Black Testing rubber Dispersion Instrument material Instrument Co., Ltd. 2 Hardness GB/T Sclerometer LX-A Shanghai 531.1-2008 (Shao A) LiuLing Instrument Plant 3 Tensile GB/T Servo Con- A1-3000 High Iron Strength 528-2009 trol Tensile Testing (Mpa) Testing Instrument Machine Co., Ltd. 4 Elongation at GB/T Servo Con- A1-3000 High Iron Break (%) 528-2009 trol Tensile Testing Testing Instrument Machine Co., Ltd. 5 Rebound GB/T Resilience GT-7042-RE High Iron Resilience (%) 1681-2009 Tester Testing Instrument Co., Ltd. 6 Heat GB/T Heat RH-2000N High Iron Build-up 1687-1993 Build-up Testing Tester Instrument Co., Ltd. 7 Abrasion GB/T DIN GT7012-A High Iron Tester 1689-1998 Abrasion Testing Tester Instrument Co., Ltd.

(5) 2. Examples and Comparative Examples

(6) Raw material.

(7) Synthesis polyisoprene rubber, IR-70, Qingdao Yikesi Advanced Material Co., Ltd.

(8) Solution polymerized styrene-butadiene rubber (SSBR), VSL4526-OHM, manufacturer: LANXESS.

(9) Butadiene rubber, BR9000, Sinopec Qilu Co., Ltd.

(10) White carbon black, NEWSIL165-MP, Quecheng Silicon Chemistry Co., Ltd.

(11) Zinc oxide, Dalian Zinc Oxide Factory.

(12) Stearic acid, PF1808, Malaysia Licheng Co., Ltd.

(13) Anti-aging agent 4020, Jiangsu Shengao Chemistry Co., Ltd.

(14) Anti-aging agent 264, Zhejiang Huangyan Zhedong Rubber Chemicals Co., Ltd.

(15) Anti-aging agent RD, Sinopec Nanjing Chemical Industry Co., Ltd. Chemical Plant.

(16) Silane coupling agent Si69, Nanjing Shuguang Chemical Engineering Co., Ltd.

(17) Accelerating agent CZ, Shandong ShangShu Chemistry Co., Ltd.

(18) Accelerating agent D, Shandong Shanxian Chemistry Co., Ltd.

(19) Sulfur, Wudi Jinsheng Chemistry Co., Ltd.

(20) Anti-scorching agent (CTP), Shandong Yanggu Huatai Chemical Engineering Co., Ltd.

(21) The parts in the following examples and comparative examples are parts by weight.

EXAMPLE 1

(22) 60 parts of white carbon black and 6 parts of silane coupling agent Si69 were added into 100 parts of 8% maleinoid polyisoprene solution in normal hexane. Wherein, the rubber/white carbon black/Si69/normal hexane mixture was mixed using blade mixer, and then, was injected into dryer which contains approximately 150 C. nitrogen gas to form rubber particles without solvent. The mixture of nitrogen gas which contained rubber particles in the form of powder and solvent went through cyclone separator so as to separate rubber particles so as to provide masterbatch 1 in the form of powder.

(23) The masterbatch 1 was added on open mill and coated evenly. 3.5 parts of zinc oxide, 1 part stearic acid, 1.5 parts of anti-aging agent RD, 2 parts of anti-aging agent 4020 and 1.6 parts of anti-scorching agent were added, and further, 2 parts of accelerant CZ, 1 part accelerant D, 1.6 parts of sulfur were added. Then, the materials passed the roller for batch-off. They were kept for 8 hours, and then added to 150 C. plate vulcanizing machine. They were vulcanized until positive vulcanization to provide wet vulcanized rubber 1.

COMPARATIVE EXAMPLE 1

(24) 60 parts of white carbon black and 6 parts of silane coupling agent Si69 were added to 100 parts of synthesized cis polyisoprene in an internal mixer for mixing, when a filler was mixed with rubber, 3.5 parts of zinc oxide, 1 parts of stearic acid, and 1.5 parts of anti-aging agent RD and 2 parts of 4020 were added and mixed. They were kept for 8 hours, and then, 2 parts of accelerating agent CZ, 1 part of accelerating agent DPG and 1.6 parts of sulfur were added to the premixed rubber in the open mill to prepare a mixed rubber. By batch out of the open mill, after being kept for 8 hours, the mixed rubber was vulcanized in a flat vulcanizing machine under 150 C. until positive sulfuration, so as to provide dry vulcanized rubber 1.

EXAMPLE 2

(25) 56 parts of white carbon black, 5.6 parts of silane coupling agent Si69, and 3.5 parts of zinc oxide were added to of 100 parts of 12% cis polyisoprene solution in N-hexane, the mixture of rubber, white carbon black, Si69, and N-hexane is mixed by a blade paddle stirrer, injected in a multi-elbow tube by a nozzle to make the mixed solution collided with wall of the tube in the tube, resulting in an increased dispersion of filler. Then the mixture was added to a grinder continuously for a refined dispersion. The mixture was dried in a vacuum dryer having a vacuum degree of 0.08 MPa for 20 min, so as to collect masterbatch 2.

(26) 2 parts of stearic acid and 2 parts of anti-aging agent 4020 were added to the above obtained masterbatches 2 in the internal mixer, and they were mixed for 2 min, discharged from the internal mixer, then rolled and batched out by an open mill. After mixed and kept for 8 hours, 2 parts of accelerating agent CZ, 1 part of accelerating agent D and 1.6 parts of sulfur were added in the internal mixer, mixed for 1.5 min, and discharged from the internal mixer. The obtained rubber material was batched out by the open mill, kept for 8 hours, vulcanized in a flat vulcanizing machine under 150 C. until positive sulfuration, so as to provide wet vulcanized rubber 2.

COMPARATIVE EXAMPLE 2

(27) 56 parts of white carbon black and 5.6 parts of silane coupling agent Si69 were added to 100 parts of synthesized cis polyisoprene in an internal mixer for mixing. When the filler was mixed with rubber, 3.5 parts of zinc oxide, 2 parts of stearic acid, and 2 parts of anti-aging agent 4020 were added, mixed for 4 minutes then discharged from the internal mixer, then rolled and batched out by an open mill to obtain a premixed rubber. After they were kept for 8 hours, 2 parts of accelerating agent CZ, 1 part of accelerating agent DPG and 1.8 parts of sulfur were added to the premixed rubber in the open mill to prepare a mixed rubber. By batch out of the open mill, after being kept for 8 hours, the mixed rubber was vulcanized in a flat vulcanizing machine under 150 C. until positive sulfuration, to provide dry vulcanized rubber 1.

(28) TABLE-US-00003 TABLE 3 Physical properties of wet/dry vulcanized rubbers Wet Dry Wet Dry vulcanized vulcanized vulcanized vulcanized Rubber 1 Rubber 1 Rubber 2 Rubber 3 Dispersion degree of 5.5 4.3 6.2 4.0 white carbon black Hardness, RT, Shao A. 66.8 73.5 67.8 70.0 Tensile Strength (Mpa) 27.8 27.5 28.8 28.0 Elongation at Break (%) 520 629 462 480 Rebound Resilience, 48.3 46.5 54.4 53.1 (23 C., %) Rebound Resilience, 61.8 58.5 64.8 63.4 60 C., % Bottom Temperature 21.5 22.5 20.1 21.7 Rise, C. DIN Abrasion Index 102 100 108 100

(29) Table 3 shows that under different prescriptions and procedures, the physical properties of vulcanized rubbers obtained from wet masterbatch exploit examples and dry masterbatch comparison examples. It shows that, using the same prescriptions, compared to the dry masterbatch, the wet masterbatch exhibits that the degree of filler dispersion in the rubber is largely improved, the hardness of vulcanized rubber is lower, tensile strength and elongation at Break are higher, resilience is higher, dynamic compression heat production is lower, and abrasive resistance is better as well.