A low density fluoroelastomer and its preparation method and use

Abstract

This invention belongs to the field of fluororubber preparation technology, specifically relating to a low-density fluororubber, its preparation method, and its applications. This invention, through formula selection and preparation process optimization, prepares fluororubber and its watchbands that balance low density and good performance. The fluororubber prepared by this invention has a density as low as 1.6 g / cm³. 3 It is far lower than the density of existing fluororubber, which is 1.8 g / cm³. 3 While maintaining the excellent properties of fluororubber, it achieves lightweighting by reducing density, while meeting the requirements of comfort, durability and appearance of watch straps. Moreover, the manufacturing process is simple, suitable for commercial production, and has good application prospects.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of fluoroelastomer preparation, and particularly relates to a low-density fluoroelastomer and a preparation method and use thereof. BACKGROUND

[0002] With the rapid development of the wearable device industry, the market demand for products such as smart watches is increasing, and the materials of watch bands are also becoming more diverse. As consumers, when purchasing a smart watch, in addition to focusing on the functionality of the product, wearing comfort, product durability and design fashion are also important factors in determining consumer choice, and the wearing experience, appearance effect, durability and material selection of the product are inseparable.

[0003] The watch band glue materials on the market are mainly divided into three types: silicone rubber, thermoplastic polyurethane and fluororubber. Silicone rubber is relatively soft, has poor durability, and has poor mechanical properties such as tensile strength and tear resistance. Its physical and mechanical properties are inferior to most synthetic rubbers at room temperature; thermoplastic polyurethane has wear resistance, tear resistance and can be quickly formed, and the cost of the finished product is very low, but it has a strong plastic feel and a general hand feel, and is mainly used for mobile phone cases, low-priced children's watches, etc., and the wearing comfort is also poor; fluororubber is a commonly used rubber watch band raw material, which has excellent properties such as sweat resistance and aging resistance. The watch band made of fluororubber has a dense and excellent texture, is soft, skin-friendly, sensitive, and resistant to dirt, comfortable to wear and durable, and can be prepared in a variety of popular colors, and is favored by smart watches such as Apple Watch, Huami Amazfit, Xiaomi Watch, and Huawei (HUAWEI) WATCH GT2.

[0004] However, the density of fluororubber watch bands is generally 1.9 g / cm 3 Therefore, it is of great significance to prepare a fluororubber with low specific gravity for use in the field of smart wear, without sacrificing the original durability and appearance requirements of fluororubber. SUMMARY

[0005] In view of the defects of the prior art, the present application provides a preparation process for a low-density fluororubber compound, aiming to prepare a fluororubber watch band with light weight and high durability.

[0006] The present application provides a low-density fluororubber compound, which comprises the following raw materials by weight:

[0007] 40-60 parts of fluororubber raw rubber, 40-60 parts of mixing type polyurethane rubber, 2-4 parts of vulcanizing agent, 2-5 parts of accelerator, and 15-30 parts of filler;

[0008] The mixing type polyurethane rubber is selected from at least one of mixing polyester type polyurethane rubber or mixing polyether type polyurethane rubber.

[0009] Preferably, the mixing type polyurethane rubber is selected from at least one of mixing polyester type polyurethane rubber; the mixing polyester type polyurethane rubber is selected from at least one of polycaprolactone type, polycarbonate, polybutylene adipate.

[0010] Preferably, the mixing polyester type polyurethane rubber is selected from at least one of the following products of Guangzhou Shunli Polyurethane Technology Co., Ltd. T2068 product.

[0011] Preferably, the fluororubber raw rubber is selected from at least one of dihexa type, di-24-6 type, di-24-6 high fluorine peroxide raw rubber;

[0012] And / or, the filler is selected from at least one or two of diatomite, sodium aluminum silicate, white carbon black, barium sulfate, pigment powder;

[0013] And / or, the vulcanizing agent is selected from at least one of double-25, double-24; the accelerator is selected from at least one of triallyl isocyanurate, tetramethyl thiuram disulfide, trimethylolpropane trimethacrylate, triallyl cyanurate;

[0014] And / or, the raw material further comprises a processing aid, and the processing aid is selected from at least one of palm wax, polyethylene wax, microcrystalline wax.

[0015] Preferably, the filler is selected from at least one of the following combinations:

[0016] 1) diatomite, pigment powder;

[0017] 2) sodium aluminum silicate, pigment powder;

[0018] 3) white carbon black, pigment powder;

[0019] The pigment powder is selected from at least one of titanium white powder and carbon black; the weight ratio of diatomite, sodium aluminum silicate or white carbon black to pigment powder is 4-6:2-4.

[0020] Preferably, the low-density fluororubber mixing rubber is prepared according to a preparation method comprising the following steps:

[0021] The fluororubber raw rubber is plasticized with the mixing type polyurethane rubber, and the accelerator, the filler and the vulcanizing agent are mixed to obtain the low-density fluororubber mixing rubber.

[0022] The present application provides a preparation method of the low-density fluororubber mixing rubber according to any one of the above, and the preparation method comprises the following steps:

[0023] The fluororubber raw rubber is mixed with the mixing type polyurethane rubber, and then the accelerator, filler and vulcanizing agent are added to mix, thereby obtaining the fluororubber.

[0024] The present application provides a low-density fluororubber prepared from the low-density fluororubber mixing rubber.

[0025] The present application provides a preparation method of the low-density fluororubber, which comprises the following steps: reacting the low-density fluororubber mixing rubber under the conditions of a pressure of 14-18 MPa and a temperature of 150-180 DEG C for 3-15 min, thereby obtaining the low-density fluororubber.

[0026] The present application provides the low-density fluororubber mixing rubber or the use of the low-density fluororubber in preparing wearable devices.

[0027] The term "mixing" is a term in rubber preparation and processing, which refers to mixing and mixing the raw rubber with various additives (such as vulcanizing agent, filler, accelerator, plasticizer, antioxidant, etc.) in a specific device, and the specific device includes a mixing mill.

[0028] The present application prepares the fluororubber mixing rubber and the watchband with low density and good performance by screening the formula and the preparation process. 3 , which is much lower than the density 1.8 g / cm 3 of the existing fluororubber. On the basis of maintaining the excellent performance of the fluororubber, the light weight is realized by reducing the density, and the comfort, durability and appearance requirements of the watchband are met, and the preparation process is simple, suitable for commercial production, and has good application prospect.

[0029] Obviously, according to the above content of the present application, according to the ordinary technical knowledge and conventional means in the art, other various forms of modifications, replacements or changes can be made without departing from the above technical idea of the present application.

[0030] The above content of the present application is further described in detail by the following embodiment form. However, it should not be understood that the above subject matter of the present application is limited to the following examples. Any technology realized based on the above content of the present application belongs to the scope of the present application. DETAILED DESCRIPTION

[0031] In the following examples and experimental examples, the reagents and materials not specifically described are commercially available.

[0032] Fluororubber raw rubber: 246M of Shandong Huaxia Shenzhou New Material Co., Ltd.;

[0033] Accelerator: Germany Lanxess TAIC / S;

[0034] Vulcanizing agent: Akema 101XL45-SP2 double di-25;

[0035] Hollow microbeads: 3M hollow glass microbeads S60HS;

[0036] Silicone rubber: Dongjue Silicone Group Co., Ltd. 110 methyl vinyl silicone rubber

[0037] Example 1 A low-density fluororubber compound and a watchband thereof

[0038] The low-density fluororubber compound and the watchband thereof of the present example are prepared by the following method:

[0039] (1) Preparation of the compound

[0040] First, 50 g of fluororubber raw rubber and 50 g of mixed polyester polyurethane rubber are added to a double roller mill, plasticized at room temperature, and then the roller gap is reduced so that excess rubber accumulates on the roller. 17 g of diatomite, 10 g of titanium dioxide, 3 g of accelerator, and finally 2.5 g of vulcanizing agent are added and mixed uniformly. After mixing, the roller gap is adjusted to less than 1 mm for rolling, 6 triangular packages are punched, and finally the roller gap is adjusted to 2 mm for sheeting to prepare the compound. The mixed polyester polyurethane used in the present example is T2068 product produced by Guangzhou Shunli Polyurethane Technology Co., Ltd.

[0041] (2) Preparation of the watchband

[0042] After the compound is preformed and cut into strips, it is placed in a mold and vulcanized at a pressure of 16 MPa and a temperature of 170℃ for 10 min to obtain the watchband.

[0043] The fluororubber watchband prepared by the method of the present example has a density of 1.60 g / cm 3 and good durability.

[0044] In other examples, processing aids such as palm wax, polyethylene wax, or microcrystalline wax can also be added when preparing the compound to further improve the processing performance and durability of the watchband.

[0045] In other examples, the mixed polyester polyurethane rubber can also be replaced by mixed polyether polyurethane rubber, which can achieve similar density and durability as the present example.

[0046] Example 2 A low-density fluororubber compound and a watchband thereof

[0047] The fluororubber compound and the watchband thereof are prepared according to the method of Example 1, except that the titanium dioxide is replaced by carbon black. The fluororubber watchband prepared by the method of the present example has a density of 1.58 g / cm​3 , and has good durability.

[0048] Example 3 A low density fluororubber compound and a watchband thereof

[0049] A fluororubber compound and a watchband thereof were prepared according to the method of Example 1, except that the diatomite was replaced by sodium aluminum silicate. The fluororubber watchband prepared by the method of this example had a density of 1.60 g / cm 3 , and has good durability.

[0050] Example 4 A low density fluororubber compound and a watchband thereof

[0051] A fluororubber compound and a watchband thereof were prepared according to the method of Example 1, except that the mixing polyester polyurethane was replaced by a TSE mixing polyester polyurethane rubber of Millathane 66 type from USA. The fluororubber watchband prepared by the method of this example had the same density and durability as that of Example 1.

[0052] Example 5 A low density fluororubber compound and a watchband thereof

[0053] A fluororubber compound and a watchband thereof were prepared according to the method of Example 1, except that the mixing polyester polyurethane was replaced by Urepan 640G (raw rubber) from Germany Rhein Chemie. The fluororubber watchband prepared by the method of this example had the same density and durability as that of Example 1.

[0054] Comparative Example 1

[0055] A fluororubber compound and a watchband thereof were prepared according to the method of Example 1, except that the fluororubber raw rubber was 100 g, and no mixing polyester polyurethane rubber was added.

[0056] Comparative Example 2

[0057] A fluororubber compound and a watchband thereof were prepared according to the method of Example 1, except that the fluororubber raw rubber was 100 g, no mixing polyester polyurethane rubber was added, and the diatomite was replaced by hollow microbeads.

[0058] Comparative Example 3

[0059] A fluororubber compound and a watchband thereof were prepared according to the method of Example 1, except that the mixing polyester polyurethane rubber was replaced by silicone rubber.

[0060] The technical solutions of the present application are further illustrated by experiments. The samples detected in the following experimental examples were prepared by the methods of Examples 1-3 and Comparative Examples 1-3.

[0061] Experimental Example 1 Performance study of modified fluororubber watchband

[0062] I. Experimental method

[0063] The fluoroelastomer watchband compound was prepared according to the method of Example 1-3 and Comparative Example 1-3. After the compound was preformed into a sheet, it was placed in a mold and vulcanized at a pressure of 16 MPa and a temperature of 170°C for 10 min. The hardness, density, tensile strength, elongation at break, tear strength and watchband tensile resistance were tested. The testing methods of the relevant indexes are as follows:

[0064] Hardness: GB / T 531.1-2008 "Vulcanized or thermoplastic rubber-Determination of indentation hardness-Part 1: Durometer method (Shore hardness)";

[0065] Density: GB / T 533-2008 "Vulcanized or thermoplastic rubber-Determination of density";

[0066] Tensile strength: GB / T 528-2009 "Vulcanized or thermoplastic rubber-Determination of tensile stress-strain properties";

[0067] Elongation at break: GB / T 528-2009 "Vulcanized or thermoplastic rubber-Determination of tensile stress-strain properties";

[0068] Tear strength: GB / T 529-2008 "Vulcanized or thermoplastic rubber-Determination of tear strength (trousers, angle and crescent shaped test pieces)";

[0069] Watchband tensile resistance: The standard watch case, watchband, watch buckle and ear were used, the index was 80 N, lasting for 5 s, 1 time; the tensile tester and related clamps were used, the testing speed was 30 mm / min from the natural state to the force on the watchband, the long watchband pushed the ear to the 5th hole, and the result was the force when it was broken.

[0070] II. Experimental results

[0071] 1. Selection of composite additives

[0072] The experimental results are shown in Table 1. As can be seen from the data of Example 1, Comparative Example 1 and Comparative Example 3, in Comparative Example 1, no composite additive was used, and the raw rubber was all fluoroelastomer raw rubber, the density of the compound was 1.97 g / cm 3 , which was much higher than 1.6 g / cm 3 ; in Comparative Example 3, when the silicon rubber with lighter weight was used as the composite additive, the density was reduced to 1.62 g / cm 3 , but the tensile strength, tear strength and watchband tensile resistance were all significantly reduced, indicating that when the composite additive was silicon rubber, although the density was reduced, the durability was reduced; in Example 1, when the mixed polyester type polyurethane rubber was used as the composite additive, the density was reduced to 1.62 g / cm3 Moreover, the tensile strength, elongation at break, tear strength and the band tensile strength are not only not reduced, but are improved, and in particular, the elongation at break is significantly improved. Therefore, when the composite additive is preferably the mixed polyester type polyurethane rubber, the density is reduced, and the durability of the fluorine rubber is improved, meeting the requirements of the fluorine rubber band.

[0073] Table 1

[0074]

[0075] (2) Selection of fillers

[0076] The experimental results are shown in Table 2. As can be seen from the data of Examples 1, 3 and Comparative Example 2, in Comparative Example 2, hollow glass microbeads were used to increase the volume and reduce the density, but it can be seen that the effect of reducing the density is small, and it cannot effectively meet the low density requirement; in Example 3, sodium aluminum silicate is a stronger self-reinforcing filler, but when used in the base material of low density fluorine rubber, it is found that the strength of the rubber compound is less increased, and it is less effective than the use of diatomite in Example 1. Therefore, when the filler is any one of diatomite and sodium aluminum silicate, the requirements of low density and durability can be met, and in particular, diatomite has better performance.

[0077] Table 2

[0078]

[0079]

[0080] (3) Change of color

[0081] The results are shown in Table 3. As can be seen from the data of Examples 1 and 2, changing the color of the toner can adjust the color of the rubber compound, and at the same time, the hardness, tensile properties, tear properties and band tensile properties are not significantly reduced. It shows that the rubber compound prepared by the present application has strong practicability, and the colored rubber compound meeting the requirements of low density and good performance can be prepared by adding or adjusting the toner.

[0082] Table 3

[0083] Example 1 Example 2 toner titanium dioxide carbon black hardness (Shore A) 63 65 Density (g / cm 3 )]]> 1.60 1.58 tensile strength (MPa) 21 23 elongation at break (%) 440 380 tear strength (KN / m) 34 38 band tensile force (N) 110 125

[0084] The above results show that the present application uses peroxide fluorine rubber as a base material, adds mixed polyurethane as an additive, and preferably uses diatomite or sodium aluminum silicate as a filler, to prepare a low density 1.6 g / cm 3 Rubber material, which breaks the minimum density of 1.8 g / cm 3The wristband prepared from the rubber compound can not only meet the requirements of comfort, skin-friendliness, hand feeling and the like of smart wearable products, but also has no cell stimulation or sensitization hazard, and makes up the blank of the low-density fluororubber raw material.

[0085] It can be seen from the above examples and experimental examples that the fluororubber wristband with low density and good performance is prepared by screening the formula and the preparation process. 3 , which is much lower than the density 1.8 g / cm 3 of the existing fluororubber. On the basis of maintaining the excellent performance of the fluororubber, the light weight is realized by reducing the density, the comfort, the durability and the appearance of the wristband are met, the preparation process is simple, the commercial production is suitable, and the application prospect is good.

Claims

1. A low density fluoroelastomer compound, characterized by, It comprises the following raw materials by weight: fluorine rubber 40~60 parts, mixing type polyurethane rubber 40~60 parts, vulcanizing agent 2~4 parts, accelerator 2~5 parts, filler 15~30 parts; The mixing type polyurethane rubber is mixing polyester type polyurethane rubber; The filler is selected from at least one of the following combinations: 1) diatomite, pigment powder; 2) sodium aluminum silicate, pigment powder; The pigment powder is selected from at least one of titanium dioxide and carbon black; the weight ratio of diatomite or sodium aluminum silicate to pigment powder is 4~6:2~4.

2. The low density fluoroelastomer gum of claim 1, characterized in that: The mixing polyester type polyurethane rubber is selected from at least one of polycaprolactone type, polycarbonate and polybutylene adipate.

3. Low density fluoroelastomer mix according to claim 1 or 2, characterized in that: The mixing polyester type polyurethane rubber is selected from X-THANE® T2068 product of Guangzhou Shunli Polyurethane Technology Co., Ltd.

4. The low density fluoroelastomer gum of claim 1 wherein: The fluorine rubber is selected from at least one of dihexa type, di-24-6 type and di-24-6 high fluorine peroxide raw rubber; And / or, the vulcanizing agent is selected from at least one of di-25-25 and di-24-24; the accelerator is selected from at least one of triallyl isocyanurate, tetramethyl thiuram disulfide, trimethylolpropane trimethacrylate and triallyl cyanurate; And / or, the raw materials further comprise a processing aid, and the processing aid is selected from at least one of palm wax, polyethylene wax and microcrystalline wax.

5. The low density fluoroelastomer gum of claim 1 wherein, Prepared according to the following preparation method: The fluorine rubber is plasticized with the mixing type polyurethane rubber, and the accelerator, filler and vulcanizing agent are added for mixing, and the low density fluorine rubber mixing rubber is obtained.

6. A process for the preparation of the low density fluoroelastomer mix according to any one of claims 1 to 5, characterized in that, The preparation method comprises the following steps: The fluorine rubber is plasticized with the mixing type polyurethane rubber, and the accelerator, filler and vulcanizing agent are added for mixing, and the low density fluorine rubber mixing rubber is obtained.

7. A low density fluoroelastomer characterized by: The low density fluorine rubber mixing rubber is prepared according to claim 1.

8. The process for the production of the low density fluoroelastomer according to claim 7, characterized in that, The preparation method comprises the following steps: the low density fluorine rubber mixing rubber is reacted for 3~15 min under the conditions of pressure 14~18 MPa and temperature 150~180℃, and the low density fluorine rubber mixing rubber is obtained.

9. The use of the low density fluorine rubber mixing rubber according to any one of claims 1~5, or the low density fluorine rubber according to claim 7 in the preparation of wearable devices.

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