White smooth surface rubber extrusion tube and its preparation method

Abstract

This invention discloses a white, smooth-surface rubber extrusion tube and its preparation method. Using EPDM rubber as the matrix, activators, softeners, reinforcing fillers, modified phenolic resin, lubricants, white pigments, coupling agents, and vulcanization accelerators are added. These materials are mixed in a rubber mixing mill to form a mixed elastomer, which is then extruded into a pre-formed rubber tube in an extruder. The tube is then vulcanized in a vulcanizing tank to become the final product. Extruded rubber products (except silicone) are generally black, mainly because carbon black has good compatibility with rubber, which is beneficial for extrusion. Light-colored or white extruded rubber products often have poor compatibility with the fillers, resulting in rough surfaces or incomplete extrusion. This invention solves the problem of rough surfaces or incomplete pre-forming in light-colored or white rubber extrusion products, meeting different customer needs and enriching the diversity and choice of product colors.

Description

Technical Field

[0001] This invention relates to the field of rubber hose technology, and in particular to white, smooth-surfaced rubber extrusion tubes and their preparation methods. Background Technology

[0002] Rubber extrusion hoses are made from rubber as the base material, with the addition of activators, reinforcing fillers, softeners, vulcanizing agents, and accelerators to form a compound. This compound is then extruded through an extruder to form a pre-formed hose, which is subsequently vulcanized in a high-temperature vulcanizing tank or vulcanizing vessel to become the final hose product. Due to differences in the base material, rubber hoses can be classified as polar hoses and non-polar hoses. Polar hoses are mainly used for conveying non-polar oils such as mineral oil, paraffin oil, and alkane oils; non-polar hoses are mainly used for conveying water or polar oils such as dioctyl phthalate.

[0003] Most rubber hoses currently available are black, with a few being light-colored or white. They are mostly molded using silicone, which limits their applications. The reason for this is that light-colored reinforcing fillers have poor compatibility with rubber, unlike carbon black, making it difficult to extrude and form a smooth surface. Summary of the Invention

[0004] The purpose of this invention is to provide a white, smooth-surfaced rubber extrusion tube and its preparation method, so as to overcome the shortcomings of the prior art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: The white, smooth-surfaced tubing of the present invention is made from the following components in the indicated weight ratios: EPDM rubber 15%~35%; Activator 1%~5% Reinforcing filler 30%~50%; softener 0.1%~5%; Modified phenolic resin 5%~20%; Coupling agent 0.5%~3%; Lubricant 1%~6%, vulcanization accelerator 0.5%~4%; White pigment 5%~20%.

[0006] The EPDM rubber mentioned herein is one or two of EPDM8570C, EPDM2650, and EPDM6405H; the activator is zinc oxide, stearic acid, and polyvinyl alcohol 4000; the reinforcing filler is silica and magnesium oxide powder; the modified phenolic resin is one or two of LS508, 205, and ZY2000; the softener is one of paraffin oil 6030, 2250, and PM-100; the coupling agent is one or two of Si69, B-201, and KH-550; the lubricant is LS356; the vulcanization accelerator is commonly used sulfur and the rapid comprehensive accelerator EG-3; and the white pigment is titanium dioxide. The main base material used in this invention is EPDM2650, which has good flowability and is beneficial for extrusion molding. The modified phenolic resins used are LS508, 205, and ZY2000. The amount used affects the extrusion performance of the EPDM rubber compound. Too little Mooney viscosity results in high viscosity, which is detrimental to extrusion; too much results in low viscosity, which is beneficial for extrusion but leads to greater product deformation. Therefore, there is a suitable dosage range, which is 5% to 20% in this case. The lubricant is LS356, which reduces the surface friction coefficient and provides a smooth feel. Its dosage is 1% to 6%. Titanium dioxide is used as the pigment. Too little results in a yellowish product, while too much increases the cost of the compound. In this formulation, the dosage is 13.6%.

[0007] In the aforementioned white, smooth-surface rubber tubing compound, the optimized weight ratio of the compound components is as follows: EPDM rubber 15%~35%; Activator 3.3% Reinforcing filler 31.7%; Softener 3%; Modified phenolic resin 5%~20%; Coupling agent 2%; Lubricant 1%~6%, vulcanization accelerator 2.7%; White pigment 13.6%.

[0008] The EPDM rubber mentioned above is one or two of EPDM8570C, EPDM2650, and EPDM6405H; the activator is zinc oxide, stearic acid, and polyvinyl alcohol 4000, with polyvinyl alcohol 4000 serving as a high-molecular-weight surfactant. The reinforcing filler is silica and magnesium oxide powder; the modified phenolic resin is one or two of LS508, 205, and ZY2000; the softener is one of paraffin oil 6030, 2250, and PM-100; the coupling agent is one or two of Si69, B-201, and KH-550; the lubricant can be LS356; the vulcanization accelerator is commonly used sulfur and the rapid comprehensive accelerator EG-3; and the white pigment is titanium dioxide.

[0009] The method for preparing the white, smooth-surfaced rubber tube of the present invention comprises the following steps: A. Ingredients: Weigh each component according to the formula ratio. The proportions of EPDM rubber, magnesium oxide powder, silica, and modified phenolic resin are accurate to ±0.3%. The proportions of activator, coupling agent, lubricant, and softener are accurate to ±0.2%. The proportions of pigment and vulcanization accelerator are accurate to ±0.1%.

[0010] B. Mixing: Place the ingredients prepared in step A (excluding vulcanization accelerator and pigment) into an internal mixer. Under room temperature conditions, the internal mixer speed is 60-80 rpm and the pressure is 0.6-0.8 MPa. Mix and turn the rubber through the rotor and pressure hammer on the internal mixer. When the mixing temperature reaches 140-150℃, the rubber can be discharged and poured into an open mill. Turn the rubber three times, then adjust the roller gap of the open mill to 4-6 mm, calender the sheet and let it stand for later use.

[0011] C. Add vulcanization accelerator and pigment: Pour the mixed rubber compound prepared in step B above into an internal mixer, then add vulcanization accelerator and titanium dioxide pigment, knead and mix in the internal mixer. When the temperature reaches 85℃, pour it out and put it into an open mill for sizing three times and turning the rubber three times. Control the roller temperature below 60℃, then adjust the roller gap to 4~6mm, press out rubber strips and cool them for later use.

[0012] D. Extrusion molding and vulcanization: The rubber strip from step C above is placed into an extruder and extruded into a pre-formed rubber tube. The screw speed of the extruder is 15-25 rpm and the die temperature is 75-90℃. It is then pulled into a vulcanization tank by a traction line for vulcanization. The vulcanization temperature is generally between 240 and 260℃, and the vulcanization time is calculated at 1 mm / minute based on the tube wall thickness.

[0013] E. Cooling, Weighing and Packaging: The rubber hose vulcanized in step D above is pulled into a cold water tank by a traction machine to cool. The cooling water temperature is controlled at 20℃±2℃. After cooling, the rubber hose is measured and qualified. Then, it is pulled into the weighing area by the traction machine. When the specified weight is reached, the rubber hose is cut off. The cut rubber hose is wound in an I-shaped round cardboard box. The exposed part is sealed with a thin film and labeled.

[0014] In the above-mentioned method for preparing white smooth surface tubing, in step A, EPDM rubber accounts for 15-35% of the total weight; modified phenolic resin accounts for 5-20% of the total weight; and lubricant accounts for 1-6% of the total weight.

[0015] In the above-mentioned method for preparing white smooth surface rubber tubes, the discharge temperature of the internal mixer in step B should reach 140~150℃.

[0016] In the above-mentioned method for preparing white smooth surface rubber tubes, the discharge temperature of the internal mixer in step C should be below 85°C, and the roller temperature of the open mill should be controlled below 60°C.

[0017] In the above-described method for preparing white, smooth-surfaced rubber tubing, the temperature of the vulcanizing bath in step D is between 240 and 260°C.

[0018] In the above-described method for preparing white, smooth-surfaced tubing, the water temperature in the cooling tank in step E is controlled at 20℃±2℃.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The white smooth surface rubber compound of the present invention is easy to extrude, has a smooth surface, and does not burr, achieving the same effect as the black extrusion tube, and can meet the needs of industries such as industrial and consumer goods.

[0020] 2. The raw materials selected in this invention are appropriate and the compatibility between the raw materials is reasonable. The resulting products have high hardness, tensile strength, elongation and tear strength.

[0021] 3. The molded product of this invention has a smooth surface and is less prone to scratches due to friction. Detailed Implementation

[0022] The present invention will now be described in detail with reference to various embodiments: This invention discloses a white, smooth-surfaced rubber tube, which is made from the following components in the indicated weight ratios: EPDM rubber 15%~35%; Activator 1%~5% Reinforcing filler 30%~50%; softener 0.1%~5%; Modified phenolic resin 5%~20%; Coupling agent 0.5%~3%; Lubricant 1%~6%, vulcanization accelerator 0.5%~4%; White pigment 5%~20%.

[0023] The EPDM rubber is one or two of EPDM8570C, EPDM2650, and EPDM6405H; the activator is zinc oxide, stearic acid, and polyvinyl alcohol 4000, with polyvinyl alcohol 4000 serving as a high-molecular-weight surfactant. The reinforcing filler is silica and magnesium oxide powder; the modified phenolic resin is one or two of LS508, 205, and ZY2000; the softener is one of paraffin oil 6030, 2250, and PM-100; the coupling agent is one or two of Si69, B-201, and KH-550; the lubricant can be LS356; the vulcanization accelerator is commonly used sulfur and the rapid comprehensive accelerator EG-3; and the white pigment is titanium dioxide.

[0024] The method for preparing the white, smooth-surfaced rubber tube of the present invention comprises the following steps: A. Ingredients: Weigh each component according to the formula ratio. The proportions of EPDM rubber, magnesium oxide powder, silica, and modified phenolic resin are accurate to ±0.3%. The proportions of activator, coupling agent, lubricant, and softener are accurate to ±0.2%. The proportions of pigment and vulcanization accelerator are accurate to ±0.1%.

[0025] B. Mixing: Place the ingredients prepared in step A (excluding vulcanization accelerator and pigment) into an internal mixer. Under room temperature conditions, the internal mixer speed is 60-80 rpm and the pressure is 0.6-0.8 MPa. Mix and turn the rubber through the rotor and pressure hammer on the internal mixer. When the mixing temperature reaches 140-150℃, the rubber can be discharged and poured into an open mill. Turn the rubber three times, then adjust the roller gap of the open mill to 4-6 mm, calender the sheet and let it stand for later use.

[0026] C. Add vulcanization accelerator and pigment: Pour the mixed rubber compound prepared in step B above into an internal mixer, then add vulcanization accelerator and titanium dioxide pigment, knead and mix in the internal mixer. When the temperature reaches 85℃, pour it out and put it into an open mill for sizing three times and turning the rubber three times. Control the roller temperature below 60℃, then adjust the roller gap to 4~6mm, press out rubber strips and cool them for later use.

[0027] D. Extrusion molding and vulcanization: The rubber strip from step C above is placed into an extruder and extruded into a pre-formed rubber tube. The screw speed of the extruder is 15-25 rpm and the die temperature is 75-90℃. It is then pulled into a vulcanization tank by a traction line for vulcanization. The vulcanization temperature is generally between 240 and 260℃, and the vulcanization time is calculated at 1 mm / minute based on the tube wall thickness.

[0028] E. Cooling, Weighing and Packaging: The rubber hose vulcanized in step D above is pulled into a cold water tank by a traction machine to cool. The cooling water temperature is controlled at 20℃±2℃. After cooling, the rubber hose is measured and qualified. Then, it is pulled into the weighing area by the traction machine. When the specified weight is reached, the rubber hose is cut off. The cut rubber hose is wound in an I-shaped round cardboard box. The exposed part is sealed with a thin film and labeled.

[0029] Table 1: Components of the white smooth surface rubber compound of the present invention (by weight)

[0030] As shown in Table 1: In Example 1, the EPDM used is two types: EPDM8570C and EPDM2650, with a ratio of EPDM8570C:EPDM2650 = 3:7; the modified phenolic resin used is two types: LS508 and ZY2000, with a ratio of 5:2.

[0031] In Example 2, the EPDM used is two types: EPDM8570C and EPDM2650, with a ratio of EPDM8570C:EPDM2650 = 1:4; the modified phenolic resin used is two types: LS508 and ZY2000, with a ratio of 3:1.

[0032] In Example 3, the EPDM used is two types: EPDM8570C and EPDM2650, with a ratio of EPDM8570C:EPDM2650 = 1:9; the modified phenolic resin used is two types: LS508 and ZY2000, with a ratio of 3:1.

[0033] Example 1

[0034] Take the EPDM rubber, activator, reinforcing filler, modified phenolic resin, coupling agent, lubricant, and softener, weighed according to the proportions in Example 1 of Table 1 above, and pour them into an internal mixer to mix. When the temperature reaches 140~150℃, pour the rubber compound onto a two-roll mill for calendering and sheeting. Let it cool and stand for 5 hours before use. After the rubber in step C has stood for 5 hours, put it into an internal mixer, add the vulcanization accelerator and pigment, and knead and mix. When the temperature reaches 85℃, pour the rubber into a two-roll mill, and pass it through three times and turn it three times on the two-roll mill (the mixing temperature is controlled below 60℃ at this time). Then calender it into strips, cool and stand for use. The rubber strip containing vulcanization accelerator and pigment is extruded through an extruder, vulcanized in a vulcanizing tank at 240~260℃, cooled in a cooling water tank at 20±2℃, its dimensions are measured, it is weighed, and the rubber tube is wound up on a winding machine using a round I-shaped cardboard box. Finally, the exposed part of the cardboard box is sealed with a thin plastic film, thus completing the entire production process. Its physical properties are shown in Table 2.

[0035] Example 2

[0036] Take the EPDM rubber, activator, reinforcing filler, modified phenolic resin, coupling agent, lubricant, and softener, weighed according to the proportions in Example 2 of Table 1 above, and pour them into an internal mixer to mix. When the temperature reaches 140~150℃, pour the rubber compound onto a two-roll mill for calendering and sheeting. Let it cool and stand for 5 hours before use. After the rubber in step C has stood for 5 hours, put it into an internal mixer, add the vulcanization accelerator and pigment, and knead and mix. When the temperature reaches 85℃, pour the rubber into a two-roll mill, and pass it through three times and turn it three times on the two-roll mill (the mixing temperature is controlled below 60℃ at this time). Then calender it into strips, cool and stand for use. The rubber strip containing vulcanization accelerator and pigment is extruded through an extruder, vulcanized in a vulcanizing tank at 240~260℃, cooled in a cooling water tank at 20±2℃, its dimensions are measured, it is weighed, and the rubber tube is wound up on a winding machine using a round I-shaped cardboard box. Finally, the exposed part of the cardboard box is sealed with a thin plastic film, thus completing the entire production process. Its physical properties are shown in Table 2.

[0037] Example 3

[0038] Take the EPDM rubber, activator, reinforcing filler, modified phenolic resin, coupling agent, lubricant, and softener, weighed according to the proportions in Example 3 of Table 1 above, and pour them into an internal mixer to mix. When the temperature reaches 140~150℃, pour the rubber compound onto a two-roll mill for calendering and sheeting. Let it cool and stand for 5 hours before use. After the rubber in step C has stood for 5 hours, put it into an internal mixer, add the vulcanization accelerator and pigment, and knead and mix. When the temperature reaches 85℃, pour the rubber into a two-roll mill, and pass it through three times and turn it three times on the two-roll mill (the mixing temperature is controlled below 60℃ at this time). Then calender it into strips, cool and stand for use. The rubber strip containing vulcanization accelerator and pigment is extruded through an extruder, vulcanized in a vulcanizing tank at 240~260℃, cooled in a cooling water tank at 20±2℃, its dimensions are measured, it is weighed, and the rubber tube is wound up on a winding machine using a round I-shaped cardboard box. Finally, the exposed part of the cardboard box is sealed with a thin plastic film, thus completing the entire production process. Its physical properties are shown in Table 2.

[0039] Table 2: Physical properties of the white smooth surface hose of the present invention

[0040] As can be seen from Table 2, the white smooth surface tubing prepared by the present invention has high whiteness, good smooth surface, and its physical and mechanical properties meet the design requirements.

[0041] The specific embodiments described in this invention are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to replace them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims. Unless otherwise stated, the component content mentioned herein is expressed in parts by weight, which can be converted to mass percentage.

[0042] Although the present invention has been described in detail and specific embodiments have been cited, it will be apparent to those skilled in the art that various changes or modifications may be made without departing from the spirit and scope of the invention.

Claims

1. A white, smooth surfaced rubber extruded tube, characterized by: It is a compound made of EPDM rubber as the base material, with the addition of active agents, reinforcing agents, fillers, softeners, modified phenolic resin, coupling agents, lubricants, vulcanization accelerators, and white pigments. The weight ratio of its formulation is as follows: EPDM rubber 15%~35%; Activator 1%~5% Reinforcing filler 30%~50%; softener 0.1%~5%; Modified phenolic resin 5%~20%; Coupling agent 0.5%~3%; Lubricant 1%~6%, vulcanization accelerator 0.5%~4%; White pigment 5%~20%; The EPDM rubber mentioned therein is one or two of EPDM8570C, EPDM2650, and EPDM6405H; the activator is zinc oxide, stearic acid, and polyvinyl alcohol 4000; and the reinforcing filler is silica and magnesium oxide. The modified phenolic resin is one or two of LS508, 205, and ZY2000; the softener is one of paraffin oil 6030, 2250, and PM-100; the coupling agent is one or two of Si69, B-201, and KH-550; the lubricant is LS356; the vulcanization accelerator is commonly used sulfur and rapid comprehensive accelerator EG-3; and the white pigment is titanium dioxide.

2. The white light slip surface extruded rubber tube according to claim 1, characterized by: This white, smooth-surfaced extruded tube is made from the following components in the indicated weight ratios: EPDM rubber 15%~35%; Activator 3.3% Reinforcing filler 31.7%; Softener 3%; Modified phenolic resin 5%~20%; Coupling agent 2%; Lubricant 1%~6%, vulcanization accelerator 2.7%; White pigment 13.6%; The EPDM rubber mentioned therein is one or two of EPDM8570C, EPDM2650, and EPDM6405H; the activator is zinc oxide, stearic acid, and polyvinyl alcohol 4000; and the reinforcing filler is silica and magnesium oxide. The modified phenolic resin is one or two of LS508, 205, and ZY2000; the softener is one of paraffin oil 6030, 2250, and PM-100; the coupling agent is one or two of Si69, B-201, and KH-550; the lubricant is LS356; the vulcanization accelerator is commonly used sulfur and rapid comprehensive accelerator EG-3; and the white pigment is titanium dioxide.

3. The white, smooth-surfaced extruded tube according to claim 1 or 2 is a white rubber extrusion product, characterized in that... The extruded product is tubular, and the physical properties of the compound rubber are as follows: hardness 80A~85A, tensile strength ≥7MPa, elongation at break ≥300%, tear strength ≥25N / mm, and density ≤1.5g / cm3.

4. The method for preparing a white, smooth-surfaced tubing according to claim 1 or 2, the method comprising the following steps: A. Ingredients: Weigh each component according to the formula ratio. The proportions of EPDM rubber, magnesium oxide powder, silica, and modified phenolic resin are accurate to ±0.3%; the proportions of activators, coupling agents, lubricants, and softeners are accurate to ±0.2%; and the proportions of pigments and vulcanization accelerators are accurate to ±0.1%. B. Mixing: Put the above-prepared ingredients (except for vulcanization accelerator and pigment) into an internal mixer. Under room temperature conditions, knead and turn the rubber by the rotor and pressure hammer on the internal mixer. When the temperature reaches 140~150℃, discharge the rubber and pour it into the open mill. Turn the rubber three times, then adjust the roller gap of the open mill to 4~6mm, calender the sheet and let it stand for later use. C. Vulcanization accelerator and pigment: After the rubber compound mixed in step B has been left to stand for 5 hours, put it into an internal mixing mill, add vulcanization accelerator and pigment, knead and mix. When the rubber temperature reaches 85℃, discharge the rubber and pour it into a two-roll mill. Slide the rubber through the two-roll mill three times, and then turn the rubber over three times to produce rubber strips for later use. D. Extrusion molding and vulcanization: The rubber strip from step C above is put into an extruder and extruded into a rubber tube pre-product. It is then pulled into a vulcanization tank by a traction line for vulcanization. The vulcanization temperature is generally between 240 and 260°C. E. Cooling, Weighing and Packaging: The rubber hose vulcanized in step D above is pulled into a cold water tank by a traction machine to cool. The cooling water temperature is controlled at 20℃±2℃. After cooling, the rubber hose is measured and qualified. Then, it is pulled into the weighing area by the traction machine. When the specified weight is reached, the rubber hose is cut off. The cut rubber hose is wound in an I-shaped round cardboard box. The exposed part is sealed with a thin film and labeled.

5. The method for preparing a white, smooth-surfaced tubing according to claim 4, characterized in that: In step A, the weight ratio of EPDM rubber to modified phenolic resin is 4~0.5; the weight ratio of EPDM rubber to titanium dioxide is 3~1; and the weight ratio of EPDM rubber to lubricant is 20~10.

6. The method for preparing a white, smooth-surfaced tubing according to claim 4, characterized in that: The mixing temperature in step B is 140~150℃.

7. The method for preparing a white, smooth-surfaced tubing according to claim 4, characterized in that: The kneading temperature in step C shall not exceed 85°C.

8. The method for preparing a white, smooth-surfaced tubing according to claim 4, characterized in that: In step D, the temperature of the vulcanizing tank is between 240 and 260°C.

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