Continuous manufacturing process for rubber masterbatch and rubber masterbatch prepared therefrom

Abstract

Disclosed are a continuous manufacturing process for a rubber masterbatch and a rubber masterbatch prepared therefrom. The manufacturing process comprises: 1): a filler is added to a rubber solution, forming a rubber/filler/solvent mixture by stirring; 2): the rubber/filler/solvent mixture obtained in step 1) is fed into a coagulator, and is coagulated after optionally being brought into contact and mixed with one or more fluids of nitrogen, steam, water, aqueous slurry of filler, and oil in the coagulator, resulting in a mixture of a rubber/filler composite and a solvent; 3): the mixture obtained in step 2) is directly passed into a heating medium at a temperature higher than the boiling point of the solvent, the polarity of the medium being different from that of the solvent used, the mixture is coagulated and deswelled, and the solvent is evaporated rapidly, thereby forming a mixture of a rubber/filler composite and the solvent containing the heating medium; and 4): the solvent is removed and the remaining mixture is dried, resulting in a rubber/filler masterbatch.

Claims

1. A method for continuously producing a rubber masterbatch comprising: 1) adding a filler in a rubber solution, and stirring to form a rubber/filler/solvent mixture; 2) adding the rubber/filler/solvent mixture of step 1) into a coagulator, and optionally contacting and mixing with one or more fluid selected from the group consisting of nitrogen gas, water vapor, water, slurry of filler and oil so as to coagulate, resulting in a mixture of rubber/filler composite and the solvent; 3) adding the mixture obtained in step 2) directly into a heating medium with a temperature higher than the boiling point of the solvent, in which the polarity of the heating medium is different from that of the solvent, the mixture being further coagulated and deswollen, and the solvent being evaporated quickly so as to form a mixture of rubber/filler composite containing the heating medium as well as the solvent; 4) removing the solvent and drying the remaining mixture to obtain a rubber/filler masterbatch; wherein step 3) is implemented in a tank container; wherein the heating medium in step 3) is water, the solvent is a hydrocarbon solvent having a boiling point lower than 100° C., and optionally by vacuum drying, heat drying or extrusion heat drying for removal of water, the rubber/filler masterbatch is obtained; wherein, the solvent evaporated in step 4) and the monomers not reacted in the synthesis of rubber access into a condenser and a fractionator for recycling, the heating medium is separated, and the mixture separated from the heating medium is transferred into a heating conveyer-belt type dryer and dried in vacuum, inert gas or air; alternatively, the solvent evaporated in step 4) and the monomers not reacted in the synthesis of rubber access into a condenser and a fractionator for recycling, and then, the remaining mixture is processed by extrusion heat drying.

2. The method according to claim 1, wherein the solvent as removed in step 4) is recovered for recycling.

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

4. The method according to claim 1, wherein step 3) is implemented by using any container.

5. The method according to claim 1, wherein said heat drying is oven drying or air drying.

6. The method according to claim 1, wherein the extrusion heat drying comprises firstly extrusion to remove the heating medium, and then a further drying.

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

8. The method according to claim 7, wherein said mechanical drying is performed using an open mill, kneading machine, internal mixer, continuous internal mixer, single-screw extruder, or twin-screw extruder.

9. A rubber masterbatch prepared by a method comprising: 1) adding a filler in a rubber solution, and stirring to form a rubber/filler/solvent mixture; 2) adding the rubber/filler/solvent mixture of step 1) into a coagulator, and optionally contacting and mixing with one or more fluid selected from the group consisting of nitrogen gas, water vapor, water, slurry of filler and oil so as to coagulate, resulting in a mixture of rubber/filler composite and the solvent; 3) adding the mixture obtained in step 2) directly into a heating medium with a temperature higher than the boiling point of the solvent, in which the polarity of the heating medium is different from that of the solvent, the mixture being further coagulated and deswollen, and the solvent being evaporated quickly so as to form a mixture of rubber/filler composite containing the heating medium as well as the solvent; 4) removing the solvent and drying the remaining mixture to obtain a rubber/filler masterbatch; wherein step 3) is implemented in a tank container; wherein the heating medium in step 3) is water, the solvent is a hydrocarbon solvent having a boiling point lower than 100° C., and optionally by vacuum drying, heat drying or extrusion heat drying for removal of water, the rubber/filler masterbatch is obtained; wherein, the solvent evaporated in step 4) and the monomers not reacted in the synthesis of rubber access into a condenser and a fractionator for recycling, the heating medium is separated, and the mixture separated from the heating medium is transferred into a heating conveyer-belt type dryer and dried in vacuum, inert gas or air; alternatively, the solvent evaporated in step 4) and the monomers not reacted in the synthesis of rubber access into a condenser and a fractionator for recycling, and then, the remaining mixture is processed by extrusion heat drying.

10. A rubber article prepared by using the rubber masterbatch according to claim 9.

11. The method according to claim 1, wherein the tank container is a cylindrical tank container.

12. The method according to claim 1, further comprising using the rubber masterbatch to prepare a rubber article.

13. The rubber masterbatch according to claim 9, wherein the tank container is a cylindrical tank container.

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.

1. THE EXPERIMENTAL DATA OF THE EXAMPLES IS DETERMINED BY THE FOLLOWING EQUIPMENTS AND MEASURING METHODS

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

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

2. EXAMPLES AND COMPARATIVE EXAMPLES

(4) Raw material.

(5) Synthetic polyisoprene rubber, IR-70, Qingdao Yikesi New Material Co., Ltd.

(6) White carbon black, NEWSIL1165-MP, Wuxi Quecheng silicon Chemical Co., Ltd.

(7) Zinc oxide, Dalian Zinc Oxide Co., Ltd.

(8) Stearic acid, PF1808, Malaysia Integrated Fortune Sdn. Bhd.

(9) Anti-aging agent 4020, Jiangsu Sinorgchem Technology Co., Ltd.

(10) Silane coupling agent Si69, Nanjing Shuguang Chemical Group Co., Ltd.

(11) Accelerating agent CZ, Shandong Sunsine Chemical Co., Ltd.

(12) Accelerating agent DPG, Shandong Shanxian County Chemical Co., Ltd.

(13) Sulfur, Wudi Jinsheng Chemical Co., Ltd.

Comparison Example 1

Comparative Example 1

(14) 56 parts of white carbon black and 5.6 parts of silane coupling agent Si69 were added to 100 parts of synthetic cis polyisoprene in an internal mixer for mixing, when a 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. It was kept for 8 hours, and then, 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. It was batched out from the open mill, and after it was kept for 8 hours, the mixed rubber was vulcanized in a flat vulcanizing machine under 150° C. until positive sulfuration, to prepare dry vulcanized rubber 1.

Example 1

(15) 56 parts of white carbon black, 5.6 parts of silane coupling agent Si69, and 3.5 parts of zinc oxide were added to 100 parts of 12% cis polyisoprene solution in N-hexane, the mixture of rubber, white carbon black, Si69, and N-hexane was 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, and a refinedly dispersed mixture was obtained. The mixture was then injected into a cone coagulator with four inlets by two inlets of the cone coagulator under the pressure of 30 MPa, and at the same time, nitrogen with a temperature of about 180° C. was added to the cone coagulator from the other two inlets thereof continuously. The obtained mixture was directly injected from the outlet of the coagulator into water of about 95° C. The obtained mixture was injected into a dryer filled with nitrogen with a temperature of about 150° C. continuously, the solvent and water was volatilized, and de-solvent rubber particles were formed. Then, the mixture of nitrogen and solvent containing powered rubber particles passed a cyclone separator to obtain powered masterbatch 1, and the solvent and water was recycled through condensation.

Example 2

(16) 56 parts of white carbon black, 5.6 parts of silane coupling agent Si69, and 3.5 parts of zinc oxide were added to 100 parts of 12% cis polyisoprene solution in N-hexane, the mixture of rubber, white carbon black, Si69, and N-hexane was 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, and a refinedly dispersed mixture was obtained. The mixture was then injected into a cone coagulator with four inlets by two inlets of the cone coagulator under the pressure of 30 MPa, and at the same time, water with a temperature of about 95° C. was added to the cone coagulator from the other two inlets thereof continuously. The obtained mixture was directly injected from the outlet of the coagulator into water of about 95° C. The coagulated de-solvent rubber particles were filtered for separation with water, dried in a vacuum dryer having a vacuum degree of −0.08 MPa for 20 min, collected, so as to provide masterbatch 2.

Example 3

(17) 56 parts of white carbon black, 5.6 parts of silane coupling agent Si69, and 3.5 parts of zinc oxide were added to 100 parts of 12% cis polyisoprene solution in N-hexane, the mixture of rubber, white carbon black, Si69, and N-hexane was 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, and a refinedly dispersed mixture was obtained. The mixture was then injected into a cone coagulator with four inlets by two inlets of the cone coagulator under the pressure of 30 MPa, and at the same time, water vapor under the pressure of 0.5 MPa was added to the cone coagulator from the other two inlets thereof continuously. The obtained mixture was directly injected from the outlet of the coagulator into water of about 95° C. The coagulated de-solvent rubber particles are filtered for separation with water, dried in a single screw extruder for 3 min so as to provide master batch 3.

(18) 2 parts of stearic acid and 2 parts of anti-aging agent 4020 were added to the above obtained masterbatches 1-3 in the internal mixer, and they were mixed for 4 min., discharged from the internal mixer, then rolled and batched out by an open mill. After it was mixed and then kept for 8 hours, 2 parts of accelerating agent CZ, 1 part of accelerating agent D and 1.8 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, and kept for 8 hours, vulcanized in a flat vulcanizing machine under 150° C. until positive sulfuration, so as to provide wet vulcanized rubber 1, 2 and 3.

(19) TABLE-US-00003 TABLE 3 Physical properties of vulcanized rubber Dry Wet Wet Wet vulcanized vulcanized vulcanized vulcanized Rubber Rubber 1 Rubber 2 Rubber 3 Dispersion degree of 4.0 7.7 8.2 8.2 white carbon black Hardness, RT, Shao A. 70.0 64.0 63.0 62.8 Tensile Strength (Mpa) 28.0 28.1 28.8 29.0 Elongation at Break (%) 480.0 505.0 460.0 448.0 Rebound Resilience, 53.1 54.0 56.0 57.1 (23° C., %) Rebound Resilience, 63.4 55.2 66.1 68.2 60° C., % Bottom Temperature 21.7 19.4 17.8 15.8 Rise, ° C. DIN Abrasion Index 100.0 105.0 105.0 108.0

(20) As shown in Table 3, using the same prescriptions, due to the different wet mixed rubber drying methods, the properties of the prepared vulcanized rubber are also different. Compared with the dry masterbatch, the dispersion degree of filler in wet masterbatch is greatly improved in the rubber, the tensile strength, rebound resilience and abrasion resistance of the vulcanized rubber are apparently improved, and heat generated by compression fatigue is reduced.