Preparation process of high color fastness rubber band

Abstract

The application provides a preparation process of high color fastness rubber band, and relates to the technical field of rubber production. The preparation process is as follows: organic pigment is mixed with acetone and dioctyl phthalate, high-pressure treatment is conducted, and then acetone is removed to prepare color master batch; natural rubber, latex, hydroxy acrylate, titanium white, light stabilizer and antioxidant are mixed to prepare rubber master batch; the rubber master batch and the color master batch are mixed and subjected to temperature change treatment, and then vulcanizing agent is added for vulcanization. The application overcomes the defects of the prior art, effectively improves the color fastness while guaranteeing the basic performance of the natural rubber in the preparation of the rubber band, and increases the market prospect.

Description

Technical Field

[0001] This invention relates to the field of rubber production technology, and specifically to a preparation process for high color fastness rubber bands. Background Technology

[0002] Rubber bands are generally made of rubber and latex to create elastic materials used for binding, etc. They are characterized by high elongation, good resilience, low price, and ease of use. With technological advancements, the raw materials for rubber bands now include not only natural rubber but also materials that do not require vulcanization, such as TPR / TPE.

[0003] Currently, natural rubber and TPE rubber bands have the best overall mechanical properties, and TPE rubber bands have better aging resistance. However, TPE rubber bands are more expensive, resulting in poor economic benefits in production and sales. As a result, most basic rubber bands on the market are made of natural rubber. In actual use, the properties of natural rubber itself lead to poor color fastness of natural rubber bands, which limits the application of natural rubber rubber bands in high-end fields. Therefore, improving the color fastness of natural rubber rubber bands has significant market value. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a manufacturing process for high color fastness rubber bands, which effectively improves color fastness while ensuring the basic properties of rubber bands made from natural rubber, thereby increasing market prospects.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A process for preparing a high color fastness rubber band, the process comprising the following steps: S1. Preparation of color masterbatch: Mix organic pigment with acetone and dioctyl phthalate thoroughly and evenly, then pressurize to 0.4-0.6 MPa and stir at 1200-1400 r / min for 10-15 min, then remove acetone to obtain color masterbatch. S2. Preparation of rubber masterbatch: After mixing natural rubber and latex, hydroxyl acrylate, titanium dioxide, light stabilizer and antioxidant are added and pre-mixed to obtain rubber masterbatch for later use. S3. Raw material pretreatment: Add the above color masterbatch to the rubber masterbatch, mix and stir at 40-60℃ for 40-60 minutes, then let stand at 0℃ for 1-2 hours, and then stir at 90-95℃ for 10-15 minutes. Repeat the standing at 0℃ and stirring at 90-95℃ 3-5 times, then return to room temperature and add vulcanizing agent. Stir evenly to obtain pretreated material. S4. Vulcanization: After extruding the above pretreated material, vulcanize it at 140-150℃ and then cut it to obtain a high color fastness rubber band.

[0006] Preferably, in step S1 above, the mass ratio of organic pigment, acetone and dioctyl phthalate is 2-3:4-5:1.

[0007] Preferably, in step S2, the mass ratio of natural rubber, latex, hydroxyl acrylate, titanium dioxide, light stabilizer and antioxidant is 30-50:8-10:0.02-0.04:0.1-0.15:0.01-0.02:0.01-0.02.

[0008] Preferably, the titanium dioxide in step S2 has a particle size of 0.2-0.3 μm. Preferably, the antioxidant in step S2 is at least one of antioxidant 4010, antioxidant 4020 and antioxidant 4010.

[0009] Preferably, the light stabilizer in step S2 is light stabilizer 770.

[0010] Preferably, in step S3, the mass ratio of color masterbatch to rubber masterbatch is 1:50-60.

[0011] Preferably, the stirring speed in step S3 is 120-200 r / min.

[0012] Preferably, the vulcanizing agent in step S3 is obtained by mixing insoluble sulfur, accelerator DM, and accelerator CZ in a mass ratio of 2.5:0.8:0.5.

[0013] This invention provides a manufacturing process for high color fastness rubber bands, which has the following advantages compared with existing technologies: This invention involves uniformly mixing organic pigments with acetone and dioctyl phthalate. After the dioctyl phthalate is dissolved in acetone, it is mixed with the organic pigments under high pressure and high speed, and then the acetone is removed. This effectively improves the stability of the subsequent binding between the organic pigments and dioctyl phthalate, and enhances the uniformity of pigment dispersion. Furthermore, after mixing multiple raw materials, a low-temperature static and high-temperature stirring method is used to perform cyclic pretreatment on the raw materials, so that the components of the raw materials work together to improve the final aging resistance effect and further enhance the color fastness. Detailed Implementation

[0014] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0015] The organic pigment used below is benzidine yellow, the light stabilizer is light stabilizer 770, the antioxidant is antioxidant 4020; the vulcanizing agent is insoluble sulfur, accelerator DM and accelerator CZ mixed in a mass ratio of 2.5:0.8:0.5.

[0016] Example 1: Preparation of rubber bands: (1) Mix benzidine yellow, acetone and dioctyl phthalate in a mass ratio of 2.5:4.5:1 and stir evenly. Then pressurize to 0.5 MPa and stir at 1200 r / min for 15 min. Then remove acetone to obtain color masterbatch. (2) Prepare materials according to the following mass ratio: natural rubber: latex: hydroxy acrylate: titanium dioxide: light stabilizer: antioxidant = 40: 9: 0.03: 0.12: 0.01: 0.02; after mixing natural rubber and latex, add hydroxy acrylate, titanium dioxide, light stabilizer and antioxidant, and initially mix at 40℃ for 20 minutes to obtain rubber masterbatch; (3) Add the above color masterbatch to the rubber masterbatch at a mass ratio of 1:55, mix and stir at 160 r / min at 50℃ for 50 min, then let it stand at 0℃ for 1.5 h, and then stir at 160 r / min at 90℃ for 15 min. Repeat the 0℃ standing and 90℃ stirring operation 4 times, then restore to room temperature and add vulcanizing agent, stir evenly to obtain pretreated material; (4) The above pretreated material is extruded at 120°C, then vulcanized at 143°C and cut to obtain rubber bands.

[0017] Comparative Example 1: Preparation of rubber bands: (1) Mix benzidine yellow, acetone and dioctyl phthalate in a mass ratio of 2.5:4.5:1 and stir evenly. Then remove the acetone to obtain the color masterbatch. (2) Prepare materials according to the following mass ratio: natural rubber: latex: hydroxy acrylate: titanium dioxide: light stabilizer: antioxidant = 40: 9: 0.03: 0.12: 0.01: 0.02; after mixing natural rubber and latex, add hydroxy acrylate, titanium dioxide, light stabilizer and antioxidant, and initially mix at 40℃ for 20 minutes to obtain rubber masterbatch; (3) Add the above color masterbatch to the rubber masterbatch at a mass ratio of 1:55, mix and stir at 160 r / min at 50℃ for 50 min, then let it stand at 0℃ for 1.5 h, and then stir at 160 r / min at 90℃ for 15 min. Repeat the 0℃ standing and 90℃ stirring operation 4 times, then restore to room temperature and add vulcanizing agent, stir evenly to obtain pretreated material; (4) The above pretreated material is extruded at 120°C, then vulcanized at 143°C and cut to obtain a high color fastness rubber band.

[0018] Comparative Example 2: Preparation of rubber bands: (1) Mix benzidine yellow and dioctyl phthalate at a mass ratio of 2.5:1 and stir evenly to obtain a color masterbatch; (2) Prepare materials according to the following mass ratio: natural rubber: latex: hydroxy acrylate: titanium dioxide: light stabilizer: antioxidant = 40: 9: 0.03: 0.12: 0.01: 0.02; after mixing natural rubber and latex, add hydroxy acrylate, titanium dioxide, light stabilizer and antioxidant, and initially mix at 40℃ for 20 minutes to obtain rubber masterbatch; (3) Add the above color masterbatch to the rubber masterbatch at a mass ratio of 1:55, mix and stir at 160 r / min at 50℃ for 50 min, then let it stand at 0℃ for 1.5 h, and then stir at 160 r / min at 90℃ for 15 min. Repeat the 0℃ standing and 90℃ stirring operation 4 times, then restore to room temperature and add vulcanizing agent, stir evenly to obtain pretreated material; (4) The above pretreated material is extruded at 120°C, then vulcanized at 143°C and cut to obtain rubber bands.

[0019] Comparative Example 3: Preparation of rubber bands: (1) Mix benzidine yellow, acetone and dioctyl phthalate in a mass ratio of 2.5:4.5:1 and stir evenly. Then pressurize to 0.5 MPa and stir at 1200 r / min for 15 min. Then remove acetone to obtain color masterbatch. (2) Prepare materials according to the following mass ratio: natural rubber: latex: hydroxy acrylate: titanium dioxide: light stabilizer: antioxidant = 40: 9: 0.03: 0.12: 0.01: 0.02; after mixing natural rubber and latex, add hydroxy acrylate, titanium dioxide, light stabilizer and antioxidant, and initially mix at 40℃ for 20 minutes to obtain rubber masterbatch; (3) Add the above color masterbatch to the rubber masterbatch at a mass ratio of 1:55, mix and stir at 160 r / min at 50°C for 50 min, then stir at 160 r / min at 90°C for 60 min, then return to room temperature and add vulcanizing agent, stir evenly to obtain pretreated material. (4) The above pretreated material is extruded at 120°C, then vulcanized at 143°C and cut to obtain rubber bands.

[0020] Comparative Example 4: Preparation of rubber bands: (1) Mix benzidine yellow, acetone and dioctyl phthalate in a mass ratio of 2.5:4.5:1 and stir evenly. Then pressurize to 0.5 MPa and stir at 1200 r / min for 15 min. Then remove acetone to obtain color masterbatch. (2) Prepare materials according to the following mass ratio: natural rubber: latex: titanium dioxide: light stabilizer: antioxidant = 40: 9: 0.12: 0.01: 0.02; after mixing natural rubber and latex, add titanium dioxide, light stabilizer and antioxidant and perform preliminary mixing at 40℃ for 20 minutes to obtain rubber masterbatch; (3) Add the above color masterbatch to the rubber masterbatch at a mass ratio of 1:55, mix and stir at 160 r / min at 50℃ for 50 min, then let it stand at 0℃ for 1.5 h, and then stir at 160 r / min at 90℃ for 15 min. Repeat the 0℃ standing and 90℃ stirring operation 4 times, then restore to room temperature and add vulcanizing agent, stir evenly to obtain pretreated material; (4) The above pretreated material is extruded at 120°C, then vulcanized at 143°C and cut to obtain rubber bands.

[0021] Detection: Color fastness tests were conducted on the rubber bands prepared in each group. A spectrophotometer was used to measure the rubber bands before the experiment. L*, a*, and b* were measured at three different locations for each group of rubber band samples, and the average value was recorded as the baseline color value T0(L0, a0, b0). A lightfastness test was then conducted on each group of rubber bands (repeated three times for each group). L*, a*, and b* were measured on the rubber bands after the experiment and recorded as L1, a1, and b1. The color difference ΔE before and after the test was calculated using the following formula: The color fastness rating standard is set as follows: When ΔE ≤ 1.5, it is grade 5; when 1.5 < ΔE ≤ 3.0, it is grade 4; when 3.0 < ΔE ≤ 6.0, it is grade 3; when ΔE > 6.0, it is grade 2. The higher the grade, the better the color fastness.

[0022] The specific testing methods are as follows: Take each set of rubber bands and lay them flat on the template frame, ensuring they do not overlap or stretch, with a spacing of more than 3 cm. Place them in a xenon lamp testing machine (xenon lamp irradiation, irradiance 0.55 W / m). 2 (At 340nm) It was treated at 63±3℃ for 40h, then taken out and cooled for 2h before being detected.

[0023] The test results are shown in Table 1 below: Table 1 The tensile strength and elongation at break of the rubber bands prepared in each group were tested, and the specific results are shown in Table 2 below: Table 2 As can be seen from the above tests, the rubber band prepared in Example 1 has excellent overall mechanical properties and good color fastness.

[0024] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A manufacturing process for high color fastness rubber bands, characterized in that, The preparation process includes the following steps: S1. Preparation of color masterbatch: Mix organic pigment with acetone and dioctyl phthalate thoroughly and evenly, then pressurize to 0.4-0.6 MPa and stir at 1200-1400 r / min for 10-15 min, then remove acetone to obtain color masterbatch. S2. Preparation of rubber masterbatch: After mixing natural rubber and latex, hydroxyl acrylate, titanium dioxide, light stabilizer and antioxidant are added and pre-mixed to obtain rubber masterbatch for later use. S3. Raw material pretreatment: Add the above color masterbatch to the rubber masterbatch, mix and stir at 40-60℃ for 40-60 minutes, then let stand at 0℃ for 1-2 hours, and then stir at 90-95℃ for 10-15 minutes. Repeat the standing at 0℃ and stirring at 90-95℃ 3-5 times, then return to room temperature and add vulcanizing agent. Stir evenly to obtain pretreated material. S4. Vulcanization: After extruding the above pretreated material, vulcanize it at 140-150℃ and then cut it to obtain a high color fastness rubber band.

2. The preparation process according to claim 1, characterized in that: In step S1, the mass ratio of organic pigment, acetone, and dioctyl phthalate is 2-3:4-5:

1.

3. The preparation process according to claim 1, characterized in that: In step S2, the mass ratio of natural rubber, latex, hydroxy acrylate, titanium dioxide, light stabilizer, and antioxidant is 30-50:8-10:0.02-0.04:0.1-0.15:0.01-0.02:0.01-0.

02.

4. The preparation process according to claim 1, characterized in that: The particle size of the titanium dioxide in step S2 is 0.2-0.3 μm.

5. The preparation process according to claim 1, characterized in that: In step S2, the antioxidant is at least one of antioxidant 4010, antioxidant 4020 and antioxidant 4010.

6. The preparation process according to claim 1, characterized in that: The light stabilizer used in step S2 is light stabilizer 770.

7. The preparation process according to claim 1, characterized in that: In step S3, the mass ratio of color masterbatch to rubber masterbatch is 1:50-60.

8. The preparation process according to claim 1, characterized in that: The stirring speed in step S3 is 120-200 r / min.

9. The preparation process according to claim 1, characterized in that: The vulcanizing agent in step S3 is obtained by mixing insoluble sulfur, accelerator DM, and accelerator CZ in a mass ratio of 2.5:0.8:0.5.

Images