Lightweight rubber watchband, preparation method thereof and wristwatch

Abstract

The invention provides a lightweight rubber watchband, a preparation method thereof and a wristwatch. The light-weight rubber watchband comprises a rubber matrix and filler dispersed in the rubber matrix, the filler is at least one of hollow filler and foaming filler, and the adding amount of the filler accounts for 0.1%-20% of the weight of the rubber matrix. According to the light-weight rubber watchband disclosed by the embodiment of the invention, the overall density is reduced by adding light materials such as the hollow filler and the foaming filler, so that the light weight of the rubber watchband can be realized under the condition of the same size.

Description

Technical Field

[0001] This invention belongs to the field of wearable devices, and more specifically, relates to a lightweight rubber watch strap, its preparation method, and a wristwatch. Background Technology

[0002] With the continuous development of smart wearable products, wearing comfort has become an important criterion for consumers. Among them, skin-friendly and lightweight have become one of the main directions of current watch strap material development.

[0003] Currently, fluororubber is the mainstream strap material in the smart wearable product industry due to its superior resistance to dirt and chemicals and lower risk of allergies compared to other soft rubber materials such as silicone and TPU. However, compared to other soft rubber materials, fluororubber has a relatively high overall density (fluororubber density is approximately 2.0 g / cm³). 3 The density of silica gel is approximately 1.2 g / cm³. 3 TPU density is approximately 1.1 g / cm³. 3 As smart wearable products become increasingly segmented in the future, different product categories have higher requirements for lightweight design, with the need for weight reduction in watch straps becoming increasingly urgent.

[0004] Therefore, providing lightweight rubber watch straps is a technical problem that urgently needs to be solved. Summary of the Invention

[0005] In view of this, this application provides a lightweight rubber watch strap, its preparation method, and a wristwatch, to solve the problem of the overall high weight of watch strap materials in current wearable devices.

[0006] Some embodiments of this application provide a lightweight rubber watch strap, a method for preparing the same, and a wristwatch. The application is described below from multiple perspectives, and the embodiments and beneficial effects of these multiple perspectives can be referenced together.

[0007] Firstly, this application provides a lightweight rubber watch strap (hereinafter, sometimes simply referred to as "watch strap" or "rubber watch strap"), comprising a rubber matrix and filler dispersed in the rubber matrix. The filler is at least one of hollow filler and foamed filler, and the amount of filler added accounts for 0.1%-20% of the weight of the rubber matrix. According to embodiments of this application, the lightweight rubber watch strap utilizes lightweight filler materials, such as hollow filler, foamed filler, or a mixture of hollow filler and foamed filler, to fill the rubber matrix to reduce the overall density of the material. This effectively reduces the weight of the watch strap within the same size, achieving lightweighting. For example, within the same size (i.e., the same volume), a weight reduction of 20-30% can be achieved. However, excessive filler addition, while beneficial for weight reduction, reduces overall strength; conversely, insufficient filler addition results in limited weight reduction. Preferably, the filler addition accounts for 3%-10% of the weight of the rubber matrix, and particularly 5%-7.5%, to more effectively balance the requirements of lightweighting and strength.

[0008] As some embodiments of this application, the material of the rubber matrix may include any one or more of fluororubber, hydrogenated nitrile rubber, polyurethane rubber, silicone rubber, and polytetrafluoroethylene. The aforementioned materials have advantages such as high / low temperature resistance, corrosion resistance, and softness and skin-friendliness.

[0009] As some embodiments of this application, the hollow filler may include any one or more of hollow glass microspheres and hollow ceramic microspheres, and the foamed filler may include polymer foamed microspheres. The aforementioned materials have the advantages of being lightweight, having low thermal conductivity, high strength, and stable chemical properties. Adding them to a rubber matrix to prepare a watchband can achieve lightweighting and low cost while also possessing high strength and stability.

[0010] Hollow glass microspheres are tiny spherical powders that are hollow and contain inert gas. They not only possess advantages such as light weight and high strength, but also good flowability, heat insulation, and corrosion resistance. When filled into a rubber matrix to prepare watch straps, they ensure uniform dispersion within the rubber matrix, avoiding defects such as cracking caused by localized agglomeration. Furthermore, their heat insulation and corrosion resistance provide a better user experience and extend their service life.

[0011] For example, hollow glass microspheres may include one or more of hollow silicate glass microspheres and hollow borate glass microspheres. These hollow glass microspheres are low in cost, readily available in raw materials, and have stable performance.

[0012] In addition, hollow ceramic microspheres may include one or more of hollow zirconia ceramic microspheres and hollow alumina ceramic microspheres. These ceramic microspheres have high strength, high corrosion resistance, low cost, and are easy to color.

[0013] Furthermore, the material of the polymer foamed microspheres can be polyurethane, meaning the foaming filler can be polyurethane foamed microspheres. Polyurethane is a polymer material with excellent mechanical properties and extremely high plasticity. Polyurethane materials are further divided into polyurethane plastics, polyurethane fibers, polyurethane foam materials, and polyurethane elastomers, etc. In this application, polyurethane foamed microspheres can be used as a filler. Polyurethane foamed microspheres have better stability, chemical resistance, resilience, and mechanical properties than PVC foam materials, exhibit lower compressive deformation, and possess good thermal insulation, sound insulation, shock resistance, and anti-toxic properties. They are also lightweight, have excellent sound insulation and thermal insulation properties, are resistant to chemicals, have good electrical properties, are easy to process, and have low water absorption.

[0014] As some embodiments of this application, the particle shape of the filler includes any one or more of spherical, ellipsoidal, and teardrop shapes. These filler shapes have better flowability, are easier to disperse in the rubber matrix, and are less prone to agglomeration. Therefore, a suitable filler shape can be selected according to the comprehensive requirements of mechanical properties and molding processing.

[0015] Furthermore, the particle size of the filler can be, for example, in the range of 5-30 μm. If the particle size is too fine, it is easy for the particles to agglomerate in the rubber matrix, resulting in local defects and reduced strength. If the particle size is too coarse, the shedding of individual particles during processing can also easily cause strength loss.

[0016] As one embodiment of this application, the filler surface is modified with a coupling agent, such as one or more of silane coupling agents, titanate coupling agents, and organochromium compounds. Especially when the filler is the aforementioned hollow filler or foamed filler, the selection of a coupling agent can enable a tight bond between the inorganic phase filler and the organic phase rubber matrix, improving interfacial adhesion, thereby enhancing the compatibility between the filler and the rubber matrix and improving the performance of the watchband. In the case of hollow fillers such as hollow glass microspheres or hollow ceramic microspheres, silane coupling agents have a better effect. Silane coupling agents contain trifunctional inorganic functional groups. When used to treat the surface of, for example, hollow glass microspheres / hollow ceramic microspheres, the silane coupling agent first hydrolyzes alkoxy groups to generate silanols, which then undergo a condensation reaction with the Si-OH groups on the surface of the glass microspheres / ceramic microspheres to form chemical bonds. Compared to van der Waals forces, this results in a stronger binding force and a more stable binding state.

[0017] The amount of coupling agent added can be, for example, 1%-5% of the weight of the rubber matrix. Once the amount of coupling agent exceeds a certain level, it no longer improves the interfacial bonding strength. From a cost-reduction perspective, it is preferable to control it below 5% of the weight of the rubber matrix, more preferably below 3%. On the other hand, if the amount of coupling agent added is too low, it cannot adequately cover the filler surface, resulting in limited improvement in interfacial strength. Therefore, it is preferable to control it at 1% or more of the weight of the rubber matrix, more preferably 1.5% or more.

[0018] As one embodiment of this application, the density of the rubber matrix is ​​1.8-2.0 g / cm³. 3 The density of the filler is 0.2-0.8 g / cm³. 3 This effectively reduces the overall density of the watch strap material. It's important to note that the filler density refers to the tap density per unit volume, not the density of the material itself. For example, if the filler is hollow silicate glass microspheres, the filler density refers to the tap density of these microspheres, not the density of the silicate glass itself.

[0019] As an embodiment of this application, the rubber matrix may also contain additives, such as one or more of vulcanizing agents, color pastes, and auxiliaries. The amount of additives added accounts for 0.1%-50% of the weight of the rubber matrix, preferably 5%-30%. Among them, vulcanizing agents can promote the curing reaction of rubber, strengthen its mechanical properties, and improve its heat resistance; color pastes can meet the coloring requirements of the product; and auxiliaries can also be added to improve processing performance.

[0020] As one embodiment of this application, the additives include one or more of calcium carbonate, diatomaceous earth, and barium sulfate. Calcium carbonate can improve or enhance the tensile strength and abrasion resistance of the rubber vulcanizate, increase tear strength, adjust the Mooney viscosity of the compound, increase plasticity, facilitate rubber molding, make the product dimensions more stable, and reduce production costs. Diatomaceous earth (especially modified diatomaceous earth) is used as a reinforcing filler for the rubber matrix to enhance the physical and mechanical properties of the vulcanizate. Barium sulfate can increase the hardness of the rubber.

[0021] Secondly, this application provides a wristwatch including a lightweight rubber strap according to any of the embodiments of the first aspect described above. Since the wristwatch of this application has the lightweight rubber strap of the first aspect embodiment, it has the same / corresponding features and advantages as the lightweight rubber strap described in the first aspect.

[0022] Thirdly, this application provides a method for preparing a lightweight rubber watch strap, used to prepare a lightweight rubber watch strap according to any of the embodiments of the first aspect, comprising:

[0023] Provide watch strap blanks, which include a rubber matrix and fillers dispersed in the rubber matrix. The fillers are at least one of hollow fillers and foamed fillers, and the amount of fillers added accounts for 0.1%-20% of the weight of the rubber matrix.

[0024] The watch strap blank is pressed and molded to obtain a lightweight rubber watch strap.

[0025] It should be noted that the preparation of the watch strap in this application includes a mixing stage (i.e., the watch strap blank preparation stage, including internal mixing, open milling, and multiple re-mixing, which can typically be completed by a rubber mixing plant or mixing workshop) and a watch strap pressing and processing stage (i.e., including re-mixing, hydraulic molding, pretreatment, spraying with hand-feel oil, and boiling to prepare the watch strap, which can be completed by a watch strap factory or watch strap processing workshop). The main inventive point of the preparation method of this application, the treatment and addition of fillers, are carried out in the mixing stage. The watch strap processing stage can be carried out using existing watch strap processing methods. The following only describes the mixing stage in detail, and the detailed description of the watch strap pressing and processing stage is omitted. According to the lightweight rubber watch strap preparation method of this application, the operation is simple and reliable, the range of materials is wide, the production cost is low, and the resulting lightweight rubber watch strap has a reduced material density while maintaining mechanical properties.

[0026] As an embodiment of this application, the step of providing the watch strap blank includes:

[0027] Provide raw rubber as the rubber matrix;

[0028] Fillers are added to raw rubber and then mixed to obtain watch strap blanks.

[0029] The mixing process includes internal mixing, open milling, and multiple re-mixing. Fillers can be added during the internal mixing stage and / or the open milling stage.

[0030] Raw rubber undergoes high-temperature reactions during the stages of providing watch strap blanks, namely the mixing stage (including internal mixing, open milling, multiple re-mixing, etc., which can usually be completed by a rubber mixing plant or mixing workshop) and the watch strap pressing and processing stage (including re-mixing, hydraulic molding, pretreatment, spraying hand feel oil, boiling in water to prepare the watch strap, which can be completed by a watch strap factory or watch strap processing workshop), ultimately forming a rubber matrix.

[0031] This allows the filler to be uniformly dispersed in the raw rubber matrix during processing, resulting in a homogeneous and consistent mixed rubber, while also ensuring that the mixed rubber has appropriate plasticity to guarantee smooth processing.

[0032] As one embodiment of this application, fillers are added to raw rubber and then mixed to obtain a watch strap blank comprising:

[0033] Provide filler; treat the surface of the filler with gas plasma, the gas including one or more of inert gas and activating gas, the inert gas including argon, helium or a mixture thereof, the activating gas including one or more of carbon dioxide, nitrogen and ammonia; add the treated filler to raw rubber for mixing to obtain watch strap blank.

[0034] On the one hand, hollow glass microspheres / hollow ceramic microspheres have relatively smooth surfaces. To increase the contact area between them and the rubber matrix and thus improve their interfacial compatibility, the surface of the hollow glass microspheres can be treated to increase their surface roughness. Plasma surface treatment, such as using inert gases like argon and helium, can not only etch the surface of the microspheres to increase their surface roughness and the contact area between the microspheres and the rubber matrix, but also "anchor" the polymer chains in the raw rubber of the rubber matrix, increasing the interfacial activity of the load-bearing material.

[0035] On the other hand, hollow glass microspheres contain a large number of silanol groups on their surface, but their activity is low, making it difficult for them to participate in chemical reactions. Therefore, activating gases such as carbon dioxide, nitrogen, and ammonia can be used. The plasma from these activating gases can activate the surface of the microspheres, introducing carboxyl, amino, and hydroxyl groups. These groups can chemically bond with the molecular chains of the raw rubber, thereby further increasing the interfacial bonding force between the microspheres and the raw rubber.

[0036] As one embodiment of this application, the process of adding filler to raw rubber and mixing it to obtain a watch strap blank further includes:

[0037] The filler treated with gas plasma is subjected to coupling agent treatment. The coupling agent includes one or more of silane coupling agents, titanate coupling agents, and organochromium compounds. The amount of coupling agent added accounts for 1%-5% of the weight of the raw rubber. The filler treated with coupling agent is added to the raw rubber for mixing during the mixing stage.

[0038] In other words, in this application, after plasma treatment of the filler, such as hollow glass microspheres, a coupling agent treatment is further performed. As mentioned above, the coupling agent treatment can further increase the interfacial bonding force between the filler and the rubber matrix.

[0039] As an embodiment of this application, in the step of providing the watch strap blank, the material of the rubber matrix includes any one or more of fluororubber, hydrogenated nitrile rubber, polyurethane rubber, silicone rubber, and polytetrafluoroethylene.

[0040] As an embodiment of this application, in the step of providing the watch strap blank, the particle shape of the filler includes any one or more of spherical, ellipsoidal, and teardrop shapes.

[0041] As an embodiment of this application, in the step of providing the watch strap blank, the hollow filler includes any one or more of hollow glass microspheres and hollow ceramic microspheres, and the foamed filler includes polymer foamed microspheres.

[0042] As an embodiment of this application, hollow glass microspheres include one or more of hollow silicate glass microspheres and hollow borate glass microspheres; hollow ceramic microspheres include one or more of hollow zirconia ceramic microspheres and hollow alumina ceramic microspheres; and the material of polymer foamed microspheres includes polyurethane.

[0043] As one embodiment of this application, in the step of providing the watch strap blank, the density of the rubber matrix is ​​1.8-2.0 g / cm³. 3 The density of the filler is 0.2-0.8 g / cm³. 3 .

[0044] As an embodiment of this application, during the mixing stage, additives are also added. The additives include one or more of vulcanizing agents, color pastes, and auxiliaries, and the amount of the additives added accounts for 0.1%-50% of the weight of the rubber matrix. The auxiliaries are added during the internal mixing stage, and the vulcanizing agents and color pastes are added during the open milling stage.

[0045] As one embodiment of this application, the filler is added during the mixing stage, including:

[0046] During the mixing stage, fillers and additives are added together, including one or more of calcium carbonate, diatomaceous earth, and barium sulfate.

[0047] Specifically, when adding fillers during the mixing stage, the blades in the equipment (such as a two-roll mill) can be used for shearing and mixing, so that the fillers and additives are mixed more evenly after stirring.

[0048] In another embodiment of this application, the filler is added during the open milling stage, including:

[0049] During the initial refining stage, the filler is added simultaneously with one or more of the color paste and vulcanizing agent.

[0050] Specifically, when adding filler during the initial refining stage, manual operation is required because the plasticizing process is carried out using the shear force generated by equipment (such as a twin-roll mill). This allows for manual adjustment of the gap between the two rollers in the equipment, minimizing the compression and damage to the filler.

[0051] In another embodiment of this application, during the internal mixing stage, a portion of the filler is added together with additives, including one or more of calcium carbonate, diatomaceous earth, and barium sulfate; during the open milling stage, the remaining filler is added simultaneously with one or more of color paste and vulcanizing agent. That is, a portion of the filler is added during both the internal mixing and open milling stages.

[0052] Specifically, the open mill utilizes a two-roll mill to generate shear force for plasticizing, requiring manual operation. The distance between the two rolls can be adjusted, resulting in less compression and damage to the microspheres. The internal mixing stage primarily utilizes paddles in the equipment for shearing and blending, leading to a more uniform mixing effect. The appropriate filler can be selected based on the specific rubber matrix and filler characteristics used in the watch strap. Alternatively, a portion of filler can be added in both the internal mixing and open milling stages to balance filler damage and mixing efficiency. Attached Figure Description

[0053] Figure 1 A cross-sectional schematic diagram of a lightweight rubber watch strap according to an embodiment of this application using hollow filler as filler is shown;

[0054] Figure 2 A cross-sectional schematic diagram of a lightweight rubber watch strap according to an embodiment of this application using foamed filler as filler is shown;

[0055] Figure 3 A cross-sectional schematic diagram of a lightweight rubber watch strap according to an embodiment of this application is shown, which uses a mixture of hollow filler and foamed filler as filler.

[0056] Figure 4 A schematic diagram of the hollow filler used in the lightweight rubber watch strap according to an embodiment of this application is shown;

[0057] Figure 5 A schematic diagram of the foamed filler used in the lightweight rubber watch strap according to an embodiment of this application is shown;

[0058] Figure 6 This is a schematic flowchart of a method for preparing a lightweight rubber watch strap according to an embodiment of this application;

[0059] Figure 7 This is a schematic diagram of the mixing stage in a method for preparing a lightweight rubber watch strap according to an embodiment of this application.

[0060] Figure 8 This is a schematic diagram of the preparation process of the lightweight rubber watch strap blank of Example 1 of this application;

[0061] Figure 9 This is a schematic diagram of the preparation process of the lightweight rubber watch strap blank for Example 3 of this application.

[0062] Figure reference numerals: 1. Rubber matrix; 2. Filler; 21. Hollow filler; 22. Foamed filler. Detailed Implementation

[0063] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.

[0064] refer to Figures 1-3The diagram illustrates different fillers used in the lightweight rubber watch straps of this application. Figures 1-3 As shown, the lightweight rubber watch strap includes a rubber matrix 1 and filler 2 dispersed in the rubber matrix 1, such as... Figure 1 As shown, the packing 2 can be hollow packing 21, or, as... Figure 2 As shown, filler 2 can be foamed filler 22, or, as... Figure 3 As shown, filler 2 can be a mixture of hollow filler 21 and foamed filler 22. The amount of filler 2 added accounts for 0.1%-20% of the weight of rubber matrix 1.

[0065] It should be noted that, Figures 1-3 The illustration merely shows the filler 2 arranged in multiple rows and columns periodically within the rubber matrix 1 for ease of drawing. It does not imply that the actual product must be arranged in this periodic, orderly manner. Different arrangements will occur depending on the strap size, filler particle size, and final density requirements, combined with the processing during the mixing stage. Furthermore, when filler 2 includes both hollow filler 21 and foamed filler 22, it is not required that the hollow filler 21 and foamed filler 22 be uniformly spaced apart. Their specific distribution can also vary depending on the amount and stage of addition of the hollow filler 21 and foamed filler 22, for example, different filler 2 may be arranged in different layers.

[0066] In some implementations, a blend of fluororubber and silicone rubber is commonly used to reduce the weight of the watch strap material. The low density of silicone rubber is utilized to reduce the overall density of the blended rubber. However, the poor compatibility between different rubber materials makes phase separation easy to occur between dissimilar rubbers. Furthermore, during stretching, interface slippage can occur between different rubber materials, affecting the overall mechanical properties. According to the lightweight rubber watch strap of the above embodiment of this application, filler 2 is added to the rubber matrix 1. Filler 2 is selected from low-density hollow fillers and / or foamed materials, thereby reducing the overall density of the rubber watch strap material and achieving lightweighting of the watch strap within the same size and volume. In addition, the high strength of filler 2 itself also helps to improve the overall strength of the rubber watch strap.

[0067] In addition, hollow fillers are corrosion resistant, non-absorbent (i.e., they prevent moisture from remaining on the filler surface, effectively preventing mold growth, scaling, and other phenomena), and inexpensive. Foamed fillers are also inexpensive, which can effectively reduce production costs.

[0068] In one embodiment of this application, the material of the rubber matrix 1 may include any one or more of fluororubber, hydrogenated nitrile rubber, polyurethane rubber, silicone rubber, and polytetrafluoroethylene. Using the aforementioned materials to prepare the rubber matrix 1 gives it advantages such as high / low temperature resistance and corrosion resistance, thereby increasing the lifespan of the watch strap.

[0069] In one embodiment of this application, the hollow filler includes any one or more of hollow glass microspheres, hollow ceramic microspheres, etc. The aforementioned types of hollow fillers are selected, such as... Figure 4 As shown, it is lightweight, has low thermal conductivity, high strength, and stable chemical properties.

[0070] In one embodiment of this application, hollow glass microspheres include one or more of hollow silicate glass microspheres and hollow borate glass microspheres, and hollow ceramic microspheres include one or more of hollow zirconia ceramic microspheres and hollow alumina ceramic microspheres.

[0071] Hollow glass microspheres are tiny, spherical powders containing inert gas, typically spread out like powder in the hand. They possess advantages such as light weight and high strength, as well as good flowability, heat insulation, and corrosion resistance. Filling a rubber matrix with these hollow glass microspheres to prepare watchbands allows for uniform dispersion within the rubber matrix, preventing defects like cracking caused by localized agglomeration. Furthermore, their heat insulation and corrosion resistance result in a better user experience and longer service life.

[0072] In one embodiment of this application, the foaming filler 22 can be polymer foamed microspheres. For example... Figure 5 As shown, polymer foamed microspheres are materials with air-porous structures formed by adding foaming agents to polymer materials and then processing them through heating, expansion, and molding. Polymer foamed microsphere materials are lightweight, heat-insulating, and cushioning.

[0073] In one embodiment of this application, the material of the polymer foamed microspheres can be polyurethane foamed microspheres. For example, ETPU foamed microspheres are made from thermoplastic polyurethane (TPU) as the matrix using clean and environmentally friendly supercritical carbon dioxide foaming technology (SCF). These polyurethane foamed microspheres not only possess high modulus, high strength, wear resistance, chemical resistance, and hydrolysis resistance, but are also lightweight and material-saving, with a specific gravity below 0.2 g / ml. They also exhibit excellent resilience, with a drop ball rebound of over 55%, making them suitable for use in watch straps, simultaneously meeting the requirements of lightweight and strength.

[0074] In one embodiment of this application, the particle shape of filler 2 includes any one or more of spherical, ellipsoidal, and teardrop shapes, and the particle size of the filler is 5-30 μm. Specifically, except for spherical, ellipsoidal and teardrop-shaped fillers are anisotropic. For anisotropic fillers, the larger the aspect ratio, the stronger the reinforcing effect, which is more beneficial to improving the mechanical properties of the product, but it is detrimental to molding and processing. Furthermore, for isotropic fillers with aspect ratios close to 1, such as... Figures 4-5 The spherical filler shape shown is beneficial for the molding and processing of composite materials, but detrimental to the improvement of mechanical properties. A suitable filler shape can be selected based on the comprehensive requirements of both mechanical properties and molding / processing.

[0075] In one embodiment of this application, the surface of the filler 2 is modified with a coupling agent, which is one or more selected from silane coupling agents, titanate coupling agents, and organochromium compounds. Using a coupling agent can improve the adhesion between the surface of the filler 2 and the rubber matrix 1, thereby enhancing the compatibility between the filler 2 and the rubber matrix 1. Specifically, using a silane coupling agent can enhance the overall strength of the watchband material. Furthermore, using a titanate coupling agent can impart overall flexibility to the watchband material.

[0076] In one embodiment of this application, the density of the rubber matrix is ​​1.8-2.0 g / cm³. 3 The density of the filler is 0.2-0.8 g / cm³. 3 The addition of fillers with lower density compared to rubber matrix can effectively reduce the overall density of the watch strap material.

[0077] In one embodiment of this application, the rubber matrix further contains additives, including one or more of vulcanizing agents, colorants, and auxiliaries. The amount of additives added is 0.1%-50% of the weight of the rubber matrix.

[0078] Specifically, during preparation, adding vulcanizing agents to the rubber matrix can promote the curing reaction of the rubber, strengthen its mechanical properties, and improve its heat resistance; adding color paste can meet the color matching requirements of the product; adding additives can improve the processing performance.

[0079] In one embodiment of this application, the additives include one or more of calcium carbonate, diatomaceous earth, and barium sulfate.

[0080] Specifically, calcium carbonate can improve or enhance the tensile strength and abrasion resistance of rubber vulcanizates, increase tear strength, adjust the Mooney viscosity of the compound, increase plasticity, facilitate rubber molding, make the product dimensions more stable, and reduce production costs. Modified diatomaceous earth can be used as a reinforcing filler in the rubber matrix to enhance the physical and mechanical properties of the vulcanizate. Barium sulfate can increase the hardness of rubber but reduce its elasticity.

[0081] Furthermore, this application also provides a wristwatch including a lightweight rubber strap according to any of the embodiments of the first aspect described above. The wristwatch of this application possesses the same characteristics and effects as the lightweight rubber strap of the first aspect described above, and will not be repeated here.

[0082] The following describes, in conjunction with specific examples, a method for preparing a lightweight rubber watch strap according to an embodiment of this application, corresponding to the materials and composition of the lightweight rubber watch strap described above.

[0083] like Figure 6 As shown, the preparation method according to the embodiments of this application includes:

[0084] S1 provides watch strap blanks.

[0085] The watchband blank preparation stage, also known as the mixing stage, includes processes such as internal mixing, open milling, and multiple re-mixing. The blank preparation can be completed, for example, by a rubber compounding plant or mixing workshop, and then sent to the watchband pressing process. According to the embodiments of this application, the watchband blank includes a rubber matrix and fillers dispersed in the rubber matrix. The fillers are at least one of hollow fillers and foamed fillers, and the amount of filler added accounts for 0.1%-20% of the weight of the rubber matrix.

[0086] S2, watch strap pressing process.

[0087] Lightweight rubber watch straps are produced by pressing and molding raw materials. The watch strap pressing process may include steps such as remelting, hydraulic molding, pretreatment, spraying with hand-feel oil, and boiling in water to complete the watch strap preparation. The pressing process of watch straps can be completed, for example, in a watch strap factory or watch strap processing workshop.

[0088] The main inventive point of the preparation method of this application is that the treatment and addition of the filler are carried out in the mixing stage. The watch strap processing stage can be carried out using existing watch strap processing methods. In the further explanation of this application below, only the mixing stage will be described in detail, and the detailed description of the watch strap pressing processing stage will be omitted.

[0089] The method for preparing the lightweight rubber watch strap according to this application is simple and reliable to operate, has a wide range of material selection, and low manufacturing cost. The resulting lightweight rubber watch strap has reduced material density while maintaining mechanical properties.

[0090] As one embodiment of this application, such as Figure 7 As shown, the mixing stage may include:

[0091] S41, Providing packing material. In this process, hollow packing material, or foamed packing material, or a mixture of hollow packing material and foamed packing material is prepared.

[0092] S42, Perform gas plasma treatment on the surface of the packing material. The gas used for gas plasma treatment may include one or more of inert gases and activating gases. The inert gas includes argon, helium, or mixtures thereof. The activating gas includes one or more of carbon dioxide, nitrogen, and ammonia.

[0093] As mentioned above, on the one hand, the surface of hollow glass microspheres / hollow ceramic microspheres is relatively smooth. In order to increase the contact area between them and the rubber matrix and thus improve their interfacial compatibility, the surface of the hollow glass microspheres can be treated to increase their surface roughness. Plasma surface treatment, such as using inert gases such as argon and helium, can not only etch the surface of the microspheres to increase their surface roughness and increase the contact area between the microspheres and the rubber matrix, but also "anchor" the polymer chains in the raw rubber of the rubber matrix to increase the interfacial activity of the load material.

[0094] On the other hand, hollow glass microspheres contain a large number of silanol groups on their surface, but their activity is low, making it difficult for them to participate in chemical reactions. Therefore, activating gases such as carbon dioxide, nitrogen, and ammonia can be used. The plasma from these activating gases can activate the surface of the microspheres, introducing carboxyl, amino, and hydroxyl groups. These groups can chemically bond with the molecular chains of the raw rubber, thereby further increasing the interfacial bonding force between the microspheres and the raw rubber.

[0095] It should be noted that when the filler is a foamed filler, especially a polymer foamed microsphere, the surface of the filler can be treated with gas plasma or not. Gas plasma treatment can further change its surface roughness and the activity of surface groups.

[0096] S43, the filler after gas plasma treatment is treated with a coupling agent. According to embodiments of this application, the coupling agent may include one or more of silane coupling agents, titanate coupling agents, and organochromium compounds, and the amount of coupling agent added is 1%-5% of the weight of the raw rubber.

[0097] The selection of coupling agents can improve the adhesion between the filler surface and the rubber matrix interface, and enhance the compatibility between the filler and the rubber matrix. Specifically, the use of silane coupling agents can enhance the overall strength of the watch strap material. Furthermore, the use of titanate coupling agents can impart overall flexibility to the watch strap material.

[0098] It is also important to understand that when the filler is a foamed filler, especially a polymer foamed microsphere, the surface of the filler can be treated with a coupling agent or left untreated. Coupling agent treatment can further improve the bonding strength between the polymer foamed microsphere and the rubber matrix. S44, obtaining the watchband blank. The filler treated with the coupling agent is added to the raw rubber and mixed to obtain the watchband blank.

[0099] The following illustrations, with reference to the accompanying drawings, provide examples of watchbands prepared using different fillers introduced at different mixing stages and with varying proportions. Additionally, watchbands with the same rubber matrix but without fillers were prepared using the same process, and their weight and strength were compared.

[0100] Example 1

[0101] Figure 8 The preparation process of the watch strap blank in this example is shown. Specifically:

[0102] S51, Prepare fluororubber raw material as the rubber matrix. In this example, the fluororubber raw material is a ternary fluoropolymer with a density of 1.6-1.8 g / cm³. 3 .

[0103] S52, prepare hollow glass microspheres as fillers, and subject the hollow glass microspheres to gas plasma treatment and silane coupling agent treatment.

[0104] In this example, the hollow glass microspheres are hollow silicate glass microspheres, spherical in shape, with a density of 0.4 g / cm³. 3 The particle size is 15μm.

[0105] The surface of hollow glass microspheres was subjected to plasma gas treatment with a mixture of argon and ammonia in a ratio of 95:5 for 30 minutes.

[0106] The hollow glass microspheres, after being treated with plasma gas, are then treated with a silane coupling agent. The weight of the added silane coupling agent is 2% of the weight of the fluororubber material.

[0107] S53, in the open milling stage of compounding, the aforementioned treated hollow glass microspheres are added to the fluororubber raw rubber. The weight of the added hollow glass microspheres accounts for 5% of the weight of the fluororubber material. That is, after internal mixing, the aforementioned treated hollow glass microspheres are added in the open milling stage.

[0108] S54 produces a rubber watch strap blank. After thorough mixing (i.e., after initial milling, it undergoes multiple re-milling processes), a lightweight rubber watch strap blank can be obtained.

[0109] The above-mentioned watch strap blank can be hot-pressed to obtain a lightweight rubber watch strap. The hot-pressing temperature is 180℃ and the molding time is 5 minutes.

[0110] The resulting lightweight rubber watch strap is 15% lighter than fluororubber of the same material without hollow glass microspheres, prepared under the same process conditions.

[0111] In addition, the resulting lightweight rubber watch strap has a tensile strength of 12MPa and passes the 80N tensile durability test, meeting the requirements for watch strap use.

[0112] Furthermore, hollow glass microspheres are stably dispersed in fluororubber materials and have no compatibility issues with fluororubber materials.

[0113] Example 2

[0114] The processing steps in this example are the same as those in Example 1 and Appendix. Figure 8 The flowcharts shown are identical. The only difference is that, in this example, the filler material is hollow ceramic microspheres (hollow alumina ceramic microspheres, spherical, with a density of 0.43 g / cm³). 3 The particle size is 25μm, and the amount of silane coupling agent added is 2.5% of the weight of the fluororubber material, and the weight of the added hollow ceramic microspheres accounts for 7% of the weight of the fluororubber material.

[0115] The resulting lightweight rubber watch strap is 18% lighter than fluororubber of the same material without hollow ceramic microspheres, prepared under the same process conditions.

[0116] In addition, the resulting lightweight rubber watch strap has a tensile strength of 13MPa and passes the 80N tensile durability test, meeting the requirements for watch strap use.

[0117] Furthermore, hollow ceramic microspheres are stably dispersed in fluororubber materials and have no compatibility issues with fluororubber materials.

[0118] Example 3

[0119] Figure 9 The preparation process of the watch strap blank in this example is shown. Specifically:

[0120] S61, Prepare fluororubber raw material as the rubber matrix. In this example, the fluororubber raw material is a ternary fluoropolymer with a density of 1.6-1.8 g / cm³. 3 .

[0121] S62, polyurethane foam microspheres prepared as fillers.

[0122] In this example, the filler used is polyurethane foam microspheres (spherical, with a density of 0.2 g / cm³). 3 (Particle size is 5 μm).

[0123] In this process, the surface of the polyurethane foam microspheres was treated with plasma gas, and then the plasma-treated microspheres were treated with a silane coupling agent. The weight of the added silane coupling agent was 1.5% of the weight of the fluororubber material. In step S63, the polyurethane foam microspheres were added to the fluororubber raw rubber during the mixing stage. The weight of the added polyurethane foam microspheres accounted for 5% of the weight of the fluororubber material.

[0124] S64 is used to produce rubber watch strap blanks. After thorough mixing (i.e., internal mixing followed by open milling and multiple re-mixing), lightweight rubber watch strap blanks can be obtained.

[0125] The resulting lightweight rubber watch strap is 20% lighter than fluororubber of the same material without added polymer foam microbeads, prepared under the same process conditions.

[0126] In addition, the resulting lightweight rubber watch strap has a tensile strength of 11 MPa and passes the 80 N tensile durability test, meeting the requirements for watch strap use.

[0127] Furthermore, polyurethane foam microspheres are stably dispersed in fluororubber materials and have no compatibility issues with fluororubber materials.

[0128] As can be seen from the above examples, the preparation method of this application can use either hollow fillers or foamed microspheres as fillers. The fillers can be added in either the internal mixing stage or the open milling stage, which can achieve lightweighting while taking into account strength.

[0129] As can be seen from the above embodiments, the method for preparing lightweight rubber watch straps of the present invention has the advantages of simple operation, low cost, and high quality.

[0130] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A lightweight rubber watch strap, characterized in that, The watchband includes a rubber matrix and fillers dispersed in the rubber matrix. The fillers are at least one of hollow fillers and foamed fillers, and the amount of fillers added accounts for 0.1%-20% of the weight of the rubber matrix.

2. The lightweight rubber watch strap according to claim 1, characterized in that, The material of the rubber matrix includes any one or more of fluororubber, hydrogenated nitrile rubber, polyurethane rubber, silicone rubber, and polytetrafluoroethylene.

3. The lightweight rubber watch strap according to claim 1, characterized in that, The hollow filler includes any one or more of hollow glass microspheres, hollow ceramic microspheres, and hollow polymer materials, and the foamed filler includes polymer foamed microspheres.

4. The lightweight rubber watch strap according to claim 3, characterized in that, The hollow glass microspheres include one or more of hollow silicate glass microspheres and hollow borate glass microspheres; the hollow ceramic microspheres include one or more of hollow zirconia ceramic microspheres and hollow alumina ceramic microspheres; and the polymer foamed microspheres are made of polyurethane.

5. The lightweight rubber watch strap according to claim 1, characterized in that, The particle shape of the filler includes any one or more of spherical, ellipsoidal, and teardrop shapes, and the particle size of the filler is 5-30 μm.

6. The lightweight rubber watch strap according to claim 1, characterized in that, The filler surface is modified with a coupling agent, which is one or more of silane coupling agents, titanate coupling agents, and organochromium compounds.

7. The lightweight rubber watch strap according to claim 1, characterized in that, The density of the rubber matrix is ​​1.8-2.0 g / cm³. 3 The density of the filler is 0.2-0.8 g / cm³. 3 .

8. The lightweight rubber watch strap according to claim 1, characterized in that, The rubber matrix also contains additives, including one or more of vulcanizing agents, color pastes, and auxiliaries, and the amount of additives added accounts for 0.1%-50% of the weight of the rubber matrix.

9. The lightweight rubber watch strap according to claim 8, characterized in that, The additives include one or more of calcium carbonate, diatomaceous earth, and barium sulfate.

10. A wristwatch, characterized in that, Includes the lightweight rubber watch strap as described in any one of claims 1 to 9.

11. A method for preparing a lightweight rubber watch strap, used to prepare the lightweight rubber watch strap according to any one of claims 1 to 9, characterized in that, include: A watch strap blank is provided, the watch strap blank comprising a rubber matrix and fillers dispersed in the rubber matrix, the fillers being at least one of hollow fillers and foamed fillers, the amount of fillers added being 0.1%-20% of the weight of the rubber matrix; The watch strap blank is pressed and molded to obtain the lightweight rubber watch strap.

12. The preparation method according to claim 11, characterized in that, The step of providing the watch strap blank includes: Provide the raw rubber of the rubber matrix; The filler is added to the raw rubber and then mixed to obtain the watch strap blank. The mixing process includes internal mixing, open milling, and multiple re-mixing, and the filler is added during the internal mixing stage and / or the open milling stage.

13. The preparation method according to claim 12, characterized in that, The filler is added to the raw rubber and then mixed to obtain the watch strap blank, comprising: Provide packing material; The surface of the filler is subjected to gas plasma treatment, wherein the gas includes one or more of inert gas and activating gas, wherein the inert gas includes argon, helium or a mixture thereof, and the activating gas includes one or more of carbon dioxide, nitrogen and ammonia. The treated filler is added to the raw rubber for mixing to obtain the watch strap blank.

14. The preparation method according to claim 13, characterized in that, The addition of the filler to the raw rubber and the subsequent mixing to obtain the watchband blank further includes: The filler, after gas plasma treatment, is then treated with a coupling agent, which includes one or more of silane coupling agents, titanate coupling agents, and organochromium compounds. The amount of the coupling agent added is 1%-5% of the weight of the raw rubber. In the mixing stage, the filler treated with coupling agent is added to the raw rubber for mixing.

15. The preparation method according to claim 11, characterized in that, In the step of providing watch strap blanks The material of the rubber matrix includes any one or more of fluororubber, hydrogenated nitrile rubber, polyurethane rubber, silicone rubber, and polytetrafluoroethylene.

16. The preparation method according to claim 11, characterized in that, In the step of providing watch strap blanks The particle shape of the filler includes any one or more of spherical, ellipsoidal, and teardrop shapes, and the particle size of the filler is 5-30 μm.

17. The preparation method according to claim 11, characterized in that, In the step of providing watch strap blanks The hollow filler includes any one or more of hollow glass microspheres and hollow ceramic microspheres, and the foamed filler includes polymer foamed microspheres.

18. The preparation method according to claim 17, characterized in that, The hollow glass microspheres include one or more of hollow silicate glass microspheres and hollow borate glass microspheres; the hollow ceramic microspheres include one or more of hollow zirconia ceramic microspheres and hollow alumina ceramic microspheres; and the polymer foamed microspheres include polyurethane foamed microspheres.

19. The preparation method according to claim 11, characterized in that, In the step of providing the watch strap blank, the density of the rubber matrix is ​​1.8-2.0 g / cm³. 3 The density of the filler is 0.2-0.8 g / cm³. 3 .

20. The preparation method according to claim 12, characterized in that, During the mixing stage, additives are also added, including one or more of vulcanizing agents, color pastes, and auxiliaries. The amount of additives added accounts for 0.1%-50% of the weight of the rubber matrix. The auxiliaries are added during the internal mixing stage, while the vulcanizing agents and color pastes are added during the open milling stage.

21. The preparation method according to claim 20, characterized in that, The filler is added during the mixing stage, including: During the mixing stage, the filler is added together with the additives, which include one or more of calcium carbonate, diatomaceous earth, and barium sulfate.

22. The preparation method according to claim 20, characterized in that, The filler is added during the open milling stage, including: During the open milling stage, the filler is added simultaneously with one or more of the color paste and vulcanizing agent.

23. The preparation method according to claim 20, characterized in that, During the mixing stage, a portion of the filler is added together with the additives, the additives including one or more of calcium carbonate, diatomaceous earth, and barium sulfate; During the open milling stage, the remaining filler is added simultaneously with one or more of the color paste and vulcanizing agent.

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