Modified silicone rubber, method for preparing the same, acoustic transmissive element, and ultrasonic diagnostic apparatus

Abstract

The application relates to a modified silicone rubber, a preparation method thereof, an acoustic transmission element and an ultrasonic diagnostic device. The modified silicone rubber comprises an RTV silicone rubber cured product matrix and polystyrene microspheres dispersed in the RTV silicone rubber cured product matrix, the polystyrene microspheres are monodisperse particles, the particle size of the polystyrene microspheres is 1-20 mu m, the RTV silicone rubber cured product matrix accounts for 110-140 parts by mass in the modified silicone rubber, and the polystyrene microspheres account for 15-60 parts by mass. The modified silicone rubber can have low sound attenuation and sound reflection coefficient, good sound impedance matching characteristics and high hardness, is used as the acoustic transmission material of the ultrasonic diagnostic device, has a relatively long service life, can improve the imaging sensitivity and imaging quality of the ultrasonic diagnostic device, and has good practicability.

Description

Technical Field

[0001] This invention relates to the field of acoustic materials technology, and in particular to a modified silicone rubber and its preparation method, an acoustic transmission element, and an ultrasonic diagnostic device. Background Technology

[0002] An ultrasound probe (also known as an ultrasound transducer) is an energy converter that transforms sound signals into electrical signals and vice versa; it is a key component of medical ultrasound diagnostic equipment. Ultrasound imaging is an ultrasound diagnostic method based on an ultrasound probe. It uses harmless ultrasound waves as the information carrier. Ultrasound waves have different acoustic responses to different human tissues. By analyzing the ultrasound echo signals, ultrasound images of human tissue structures can be obtained. Due to its harmlessness and convenience, it is widely used in clinical diagnosis and intraoperative observation.

[0003] An acoustic lens, as an acoustic transmission element, is located on the outermost layer of an ultrasound probe. It needs to maximize the transmission of sound waves to improve the probe's sensitivity. Therefore, it's crucial to minimize acoustic attenuation and intensity loss. Simultaneously, improving the acoustic impedance matching between the acoustic lens and the human tissue structure enhances sound wave transmission, reduces the acoustic reflection coefficient, and improves the imaging quality of the ultrasound diagnostic equipment. Furthermore, the acoustic lens, being the outermost layer of the ultrasound probe, frequently comes into direct contact with the patient, making it prone to damage and cracking. Therefore, it requires high rigidity to extend its lifespan. However, current acoustic transmission materials struggle to simultaneously meet the demands of low acoustic attenuation and reflection coefficients, good acoustic impedance matching characteristics, and high rigidity. Consequently, it's difficult to simultaneously satisfy the requirements for long lifespan, good imaging sensitivity, and high imaging quality. Summary of the Invention

[0004] Therefore, it is necessary to provide a modified silicone rubber, its preparation method, an acoustic transmission element, and an ultrasound diagnostic device. This modified silicone rubber can be used as an acoustic transmission material in ultrasound diagnostic devices, exhibiting a long service life and enabling the ultrasound diagnostic device to possess both good imaging sensitivity and imaging quality.

[0005] The present invention is achieved through the following technical solution.

[0006] In one aspect, the present invention provides a modified silicone rubber comprising an RTV silicone rubber cured matrix and polystyrene microspheres dispersed in the RTV silicone rubber cured matrix, wherein the polystyrene microspheres are monodisperse particles and the particle size of the polystyrene microspheres is 1 μm to 20 μm.

[0007] In the modified silicone rubber, the RTV silicone rubber cured matrix is ​​110-140 parts by mass, and the polystyrene microspheres are 15-60 parts by mass.

[0008] In some embodiments, the polystyrene microspheres have a particle size of 1 μm to 10 μm;

[0009] And / or, the particle size Cv value of the polystyrene microspheres is <3%.

[0010] In some embodiments, the modified silicone rubber comprises, by weight, 110-140 parts of the RTV silicone rubber cured matrix and 15-40 parts of the polystyrene microspheres.

[0011] Another aspect of the present invention provides a method for preparing modified silicone rubber, comprising the following steps:

[0012] RTV silicone rubber, polystyrene microspheres and diluent are mixed evenly, and then a curing agent is added for curing, so that the polystyrene microspheres are dispersed in the RTV silicone rubber cured matrix formed by the curing of RTV silicone rubber;

[0013] In the modified silicone rubber, the RTV silicone rubber cured matrix is ​​110-140 parts by mass, and the polystyrene microspheres are 15-60 parts; the polystyrene microspheres are monodisperse particles with a particle size of 1μm-20μm.

[0014] In some embodiments, the RTV silicone rubber comprises 100 parts by weight, the polystyrene microspheres comprise 15 to 60 parts by weight, the diluent comprises 10 to 30 parts by weight, and the curing agent comprises 10 parts by weight.

[0015] In some embodiments, the diluent is selected from at least one of reactive diluents and non-reactive diluents;

[0016] When the diluent contains a reactive diluent, the reactive diluent participates in the curing process;

[0017] When the diluent contains a non-reactive diluent, before adding the curing agent for curing, the following step is also included: removing the non-reactive diluent from the uniformly mixed material.

[0018] The application of the modified silicone rubber described in any of the above items as a sound-permeable material.

[0019] In another aspect, the present invention provides an acoustic transmission element comprising a modified silicone rubber as described in any of the preceding claims.

[0020] In another aspect, the present invention provides an ultrasonic probe, including a probe body and the aforementioned acoustic transmission element disposed on the surface of the probe body.

[0021] In another aspect, the present invention provides an ultrasound diagnostic device, including a device host and the ultrasound probe described above.

[0022] The aforementioned modified silicone rubber and its preparation method utilize polystyrene microspheres as a modified filler for RTV silicone rubber. The polystyrene microspheres have a density comparable to RTV silicone rubber, and do not exhibit phase separation phenomena such as floating and settling within the RTV silicone rubber. They demonstrate good compatibility with RTV silicone rubber, ensuring uniform dispersion of the polystyrene microspheres within the cured RTV silicone rubber matrix. Furthermore, the selection of monodisperse polystyrene microspheres ensures highly uniform particle size. Simultaneously, the proportions of the raw materials used in the preparation of the modified silicone rubber are coordinated, resulting in excellent solid-phase homogeneity when the polystyrene microspheres fill the cured RTV silicone rubber. This leads to lower ultrasonic scattering, increasing the acoustic impedance of the resulting modified silicone rubber compared to unmodified silicone rubber. This improves its acoustic matching characteristics with human tissue, reduces the acoustic reflection coefficient, and simultaneously increases the surface hardness of the modified silicone rubber while maintaining low acoustic attenuation characteristics.

[0023] The polystyrene microspheres used in the above-mentioned modified silicone rubber do not contain polar functional groups, do not agglomerate, and have good dispersibility. They can be uniformly dispersed in silicone rubber under high-speed stirring, avoiding the problem of strong sound wave reflection caused by microsphere agglomeration, and have a low sound reflection coefficient.

[0024] The modified silicone rubber described above combines low acoustic attenuation and acoustic reflection coefficients, good acoustic impedance matching characteristics, and high hardness. When used as an acoustic transmission material in ultrasound diagnostic equipment, it not only has a long service life but also improves the imaging sensitivity and imaging quality of ultrasound diagnostic equipment, making it highly practical. Detailed Implementation

[0025] To facilitate understanding of the present invention, a more comprehensive description is provided below, along with preferred embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. It should be understood that these embodiments are provided to provide a thorough and complete understanding of the disclosure of the present invention.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0027] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0028] Based on the aforementioned technical issues, technicians attempted to use RTV silicone rubber (room temperature vulcanized silicone rubber) as an acoustic transmission material, for example, as a molding material for acoustic lenses. Specifically, taking RTV615 silicone rubber as an example, its acoustic attenuation coefficient (hereinafter referred to as acoustic attenuation) at 5MHz is only 15.4dB / cm, exhibiting low attenuation characteristics. Furthermore, the sound velocity in RTV615 silicone rubber is approximately 2 / 3 of that in human soft tissue, resulting in a low acoustic attenuation coefficient, which is highly advantageous for use as an acoustic lens material. However, the acoustic impedance of RTV615 silicone rubber is 1.05MRayl, which differs significantly from the acoustic impedance of the human body (1.5MRayl). Therefore, acoustic lenses prepared using this silicone rubber as an acoustic transmission material will exhibit significant acoustic reflection signals at the interface with the human body, leading to a reduction in transmitted sound intensity. The reflected sound waves form artifacts (interference signals) during imaging, reducing image quality and hindering ultrasound imaging. Moreover, the surface Shore hardness of this silicone rubber is 15.8, indicating low surface hardness and susceptibility to damage.

[0029] Those skilled in the art have further studied and obtained a modified silicone rubber by modifying RTV silicone rubber. The modified silicone rubber has a simple preparation process, improves acoustic matching characteristics, and has high surface hardness, low sound attenuation and sound reflection characteristics.

[0030] One embodiment of the present invention provides a modified silicone rubber, comprising an RTV silicone rubber cured matrix and polystyrene microspheres dispersed in the RTV silicone rubber cured matrix.

[0031] The polystyrene microspheres are monodisperse particles with a particle size of 1 μm to 20 μm. Furthermore, in the modified silicone rubber, the RTV silicone rubber cured matrix comprises 110 to 140 parts by mass, and the polystyrene microspheres comprise 15 to 60 parts by mass.

[0032] The density of polystyrene microspheres is 1.05 g / cm³. 3With a density comparable to that of RTV silicone rubber, polystyrene microspheres are used as a modified filler for RTV silicone rubber. Polystyrene microspheres do not exhibit phase separation phenomena such as floating and settling in RTV silicone rubber. They have good compatibility with RTV silicone rubber, which ensures the uniform dispersion of polystyrene microspheres in the cured RTV silicone rubber matrix after curing.

[0033] Furthermore, the acoustic impedance of polystyrene material is approximately 2.5 MNayl, and the acoustic attenuation at a 5 MHz acoustic frequency is only 1.7 dB / cm, exhibiting both high acoustic impedance and low acoustic attenuation characteristics. Moreover, the selection of monodisperse polystyrene microspheres ensures highly uniform particle size. Simultaneously, the proportions of the raw materials used in the preparation of the modified silicone rubber are coordinated, resulting in excellent solid-phase homogeneity when the polystyrene microspheres are filled into the RTV silicone rubber cured product. This leads to lower ultrasonic wave scattering. Compared to unmodified silicone rubber, this improves the acoustic impedance of the resulting modified silicone rubber, thereby enhancing its acoustic matching characteristics with human tissue, reducing the acoustic reflection coefficient, and simultaneously increasing the surface hardness of the modified silicone rubber while maintaining a low acoustic attenuation level.

[0034] The polystyrene microspheres used in the above-mentioned modified silicone rubber do not contain polar functional groups, do not agglomerate, and have good dispersibility. They can be uniformly dispersed in silicone rubber under high-speed stirring, avoiding the problem of strong sound wave reflection caused by microsphere agglomeration, and have a low sound reflection coefficient.

[0035] The modified silicone rubber described above combines low acoustic attenuation and acoustic reflection coefficients, good acoustic impedance matching characteristics, and high hardness. When used as an acoustic transmission material in ultrasound diagnostic equipment, it not only has a long service life but also improves the imaging sensitivity and imaging quality of ultrasound diagnostic equipment, making it highly practical.

[0036] It is understood that, in the above-mentioned modified silicone rubber, the RTV silicone rubber cured matrix can be 110 parts, 115 parts, 120 parts, 130 parts, or 140 parts by mass; the polystyrene microspheres can be 15 parts, 18 parts, 20 parts, 25 parts, 30 parts, 35 parts, 40 parts, 45 parts, 50 parts, 55 parts, or 60 parts, further 15 to 40 parts, and more preferably 20 to 40 parts.

[0037] Furthermore, in the modified silicone rubber, the RTV silicone rubber cured matrix comprises 110–140 parts by mass, and the polystyrene microspheres comprise 15–40 parts by mass.

[0038] Currently, commonly used polystyrene microspheres have particle sizes of 1μm, 10μm, 20μm, and 0.1μm. However, the 0.1μm particle size is too small; given the high viscosity of RTV silicone rubber, it is difficult for the RTV rubber to be incorporated into the 0.1μm microspheres, resulting in dispersion problems. Conversely, the larger the polystyrene microsphere particle size, the worse the diffraction effect of ultrasound in its corresponding modified silicone rubber, leading to an increase in the sound attenuation coefficient.

[0039] In some embodiments, the particle size of the polystyrene microspheres is 1 μm to 10 μm. Preferably, the particle size of the polystyrene microspheres is 1 μm. Controlling the particle size of the polystyrene microspheres within this preferred range avoids the problem of excessively small particle size leading to uneven dispersion and resulting in an inhomogeneous solid phase in the modified silicone rubber, thus increasing the acoustic attenuation coefficient. It also avoids the problem of larger particle size leading to poor ultrasonic diffraction effects, which in turn increases the acoustic attenuation coefficient. Therefore, controlling the particle size of the polystyrene microspheres within this preferred range allows the modified silicone rubber to simultaneously possess good surface Shore hardness, acoustic impedance, and a low acoustic attenuation coefficient.

[0040] In some embodiments, the particle size Cv value of the polystyrene microspheres is <3%. Here, Cv refers to the Coefficient of Variation (Cv), which is SD (standard deviation) / average particle size, representing the breadth of the particle size distribution. Further controlling the Cv value of the monodisperse polystyrene microspheres within the above range can further improve the solid-phase homogeneity of the prepared modified silicone rubber, thereby further reducing its scattering of ultrasonic waves, and thus further improving the acoustic impedance of the prepared modified silicone rubber.

[0041] Another embodiment of the present invention provides a method for preparing the above-mentioned modified silicone rubber, comprising the following steps: mixing RTV silicone rubber, polystyrene microspheres and diluent evenly, and then adding a curing agent to cure so that the polystyrene microspheres are dispersed in the RTV silicone rubber cured matrix formed by the curing of RTV silicone rubber, thereby obtaining the above-mentioned modified silicone rubber.

[0042] In some embodiments, the raw materials for the preparation method described above are as follows by mass parts: 100 parts of RTV silicone rubber, 15-60 parts of polystyrene microspheres, 10-30 parts of diluent, and 10 parts of curing agent.

[0043] Understandably, in the above-mentioned modified silicone rubber, by mass parts, the RTV silicone rubber is 100 parts; the polystyrene microspheres can be 15 parts, 18 parts, 20 parts, 25 parts, 30 parts, 35 parts, 40 parts, 45 parts, 50 parts, 55 parts, 60 parts, further 15 to 40 parts, more preferably 20 to 40 parts; and the diluent can be 10 parts, 15 parts, 20 parts, 25 parts, 30 parts.

[0044] Furthermore, by weight, the components are: 100 parts RTV silicone rubber, 15-40 parts polystyrene microspheres, 10-30 parts diluent, and 10 parts curing agent.

[0045] In some embodiments, the diluent is selected from at least one of reactive diluents and non-reactive diluents.

[0046] When the diluent contains a reactive diluent, the reactive diluent participates in the curing process. In other words, the RTV silicone rubber cured matrix is ​​cured by the aforementioned RTV silicone rubber, curing agent, and reactive diluent in parts by mass. This further increases the crosslinking density of the RTV silicone rubber cured matrix, thereby increasing the hardness of the resulting modified silicone rubber. The range of parts for the reactive diluent can be the same as the range of parts for the diluent mentioned above. In other words, the mass of the RTV silicone rubber cured matrix is ​​theoretically equivalent to the sum of the masses of the added RTV silicone rubber, curing agent, and reactive diluent.

[0047] When the diluent contains non-reactive diluents, the following step is included before adding the curing agent for curing: removing the non-reactive diluents from the uniformly mixed material. Since non-reactive diluents do not participate in curing, they can be removed before curing. It can be understood that when all diluents are non-reactive, they do not participate in curing, and theoretically, the mass of the RTV silicone rubber cured matrix is ​​equivalent to the sum of the masses of the added RTV silicone rubber and curing agent.

[0048] Furthermore, the reactive diluent is dimethyl silicone oil. Furthermore, the non-reactive diluent is ethanol.

[0049] Understandably, in some examples, the diluent may be entirely reactive or entirely non-reactive. In other examples, the diluent may be a combination of reactive and non-reactive diluents.

[0050] Furthermore, non-reactive diluents can be removed by heating, and the heating temperature can be selected according to the type of non-reactive diluent.

[0051] In some examples, the heating temperature can be 50–80°C, for example 50°C, 60°C, 70°C, or 80°C, and the time can be 1 hour–4 hours, for example 1 hour, 2 hours, 3 hours, or 4 hours. Specifically, when the non-reactive diluent is ethanol, the heating conditions for removing ethanol can be 50°C for 2 hours. Specifically, this heating step can be carried out in an oven.

[0052] Furthermore, the curing temperature can be at room temperature (20–35°C). Furthermore, the curing time can be 36 h–60 h, for example 36 h, 40 h, 45 h, 48 h, 50 h, 55 h, 60 h.

[0053] In some embodiments, the process of uniformly mixing RTV silicone rubber, polystyrene microspheres and diluent includes the following steps S21 to S22.

[0054] Step S21: Mix polystyrene microspheres and diluent to obtain polystyrene dispersion.

[0055] Step S22: Add the polystyrene dispersion to the RTV silicone rubber and mix thoroughly.

[0056] Furthermore, in step S22, the polystyrene dispersion is added to the RTV silicone rubber in stages to improve the uniformity of polystyrene dispersion in the RTV silicone rubber.

[0057] Furthermore, the step of mixing evenly can be performed using conventional methods such as mechanical stirring.

[0058] The above-mentioned method for preparing modified silicone rubber is simple and can be cured at room temperature, which is convenient for industrial production and has great practical application value.

[0059] Another embodiment of the present invention also provides the application of the modified silicone rubber of any of the above claims as a sound-permeable material.

[0060] By using the specific polystyrene microspheres and the synergistic effect of the components, the modified silicone rubber obtained after modification of RTV silicone rubber has significantly improved acoustic matching characteristics with human tissue. At the same time, the surface hardness of the modified silicone rubber is significantly increased, and it can maintain a low level of sound attenuation characteristics. Therefore, it is very suitable for use as a sound-transmitting material, such as a material for making sound-transmitting elements such as acoustic lenses.

[0061] Furthermore, another embodiment of the present invention provides the application of the modified silicone rubber of any of the above-mentioned claims in the preparation of acoustic transmission elements.

[0062] Another embodiment of the present invention provides an acoustic transmission element whose components include modified silicone rubber as described above.

[0063] In some embodiments, the acoustic transmission element may be an acoustic lens.

[0064] It is understood that the aforementioned acoustic transmission element may be made directly from the aforementioned modified silicone rubber, or it may contain other components in addition to the aforementioned modified silicone rubber.

[0065] It is understood that the aforementioned acoustic transmission element can be directly formed in a molding die using the aforementioned modified silicone rubber raw material, and then further processed as needed.

[0066] The aforementioned acoustic transmission element has a high surface hardness, which can effectively improve its service life. It also has better acoustic matching characteristics with human tissue and keeps the sound attenuation characteristics at a low level. Thus, it can reduce the sound reflection signal at the interface between the acoustic transmission element and the human body with minimal impact on sound attenuation, increase the transmitted sound intensity, and effectively reduce artifacts (interference signals) and improve imaging quality.

[0067] Another embodiment of the present invention provides an ultrasonic probe, including a probe body and the aforementioned acoustic transmission element disposed on the surface of the probe body.

[0068] Furthermore, the probe body includes a support frame and a sound-absorbing block, a crystal, and a matching layer sequentially disposed on the support frame. The acoustic transmission element is disposed on the matching layer of the probe body.

[0069] An ultrasound probe can emit and receive ultrasound waves and convert them into electroacoustic signals. The ultrasound waves emitted from the probe body are focused onto the diagnostic sample, such as tissues or organs, by an acoustic lens. The ultrasound waves that pass through the diagnostic sample carry information about the irradiated area, such as the reflection, absorption, and scattering of sound waves. They are then focused back onto the probe body by the acoustic lens, received by the probe body, and converted into an electrical signal.

[0070] The ultrasound probe uses the aforementioned acoustic transmission element, which can effectively extend its service life. Furthermore, it can reduce the acoustic reflection signal at the interface between the ultrasound probe and the human body and increase the transmitted sound intensity with minimal impact from acoustic attenuation. This effectively reduces artifacts (interference signals) and improves the quality of ultrasound imaging.

[0071] In another embodiment of the present invention, an ultrasound diagnostic device is provided, including a device host and the ultrasound probe described above.

[0072] The main unit of the device processes and displays the received signals from the ultrasonic probe. The ultrasonic probe can emit and receive ultrasonic waves and convert them into electroacoustic signals. The ultrasonic probe can convert the electrical signals transmitted from the main unit into high-frequency oscillating ultrasonic signals, and it can also convert the ultrasonic signals reflected back from diagnostic samples such as tissues and organs into electrical signals, which are finally displayed on the monitor of the main unit.

[0073] To make the objectives, technical solutions, and advantages of this invention clearer and more concise, the invention is described using the following specific embodiments, but the invention is by no means limited to these embodiments. The embodiments described below are merely preferred embodiments of the invention and can be used to describe the invention, but should not be construed as limiting the scope of the invention. It should be noted that any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the protection scope of this invention.

[0074] To better illustrate the present invention, the following examples further illustrate its content. Specific examples are as follows. The 1 μm polystyrene microspheres used in each example and comparative example were produced by Vmicro Nano's PST001UM, the 10 μm polystyrene microspheres by Vmicro Nano's PST 010UM, and the 20 μm polystyrene microspheres by Vmicro Nano's PST 020UM. The curing agent was Momentive 9482, and all had a particle size Cv value <3%.

[0075] Example 1

[0076] At 25°C, 100g of RTV615 was added to a 250mL flask. Using 10g of ethanol as a diluent, 20g of 1μm polystyrene microspheres were stirred at 25°C for 10 minutes until homogeneous, resulting in a polystyrene microsphere dispersion. This dispersion was added to the flask in four portions, one-quarter of the dispersion each time, and stirred for 10 minutes after each addition. After the addition was complete, the mixture was dried in a 50°C oven for 2 hours to remove the ethanol solvent. Then, 10g of curing agent (Momentive 9482, hereinafter the same) was added and stirred for 10 minutes. The mixture was then poured into a molding die and cured in a 25°C, 50%RH constant temperature and humidity chamber for 48 hours to obtain the RTV cured material, which is the acoustic lens material.

[0077] Example 2

[0078] At 25°C, 100g of RTV615 was added to a 250mL flask. Using 10g of ethanol as a diluent, 20g of polystyrene microspheres with a particle size of 10μm were stirred at 25°C for 10 minutes until homogeneous, resulting in a polystyrene microsphere dispersion. This dispersion was added to the flask in four portions, one-quarter of the dispersion each time, and stirred for 10 minutes after each addition. After the entire dispersion was added, the flask was dried in a 50°C oven for 2 hours to remove the ethanol solvent. Then, 10g of curing agent was added and stirred for 10 minutes. The mixture was then poured into a molding die and cured in a 25°C, 50%RH constant temperature and humidity chamber for 48 hours to obtain the RTV cured material, which is the acoustic lens material.

[0079] Example 3

[0080] At 25°C, 100g of RTV615 was added to a 250mL flask. Using 10g of dimethyl silicone oil as a diluent, 20g of polystyrene microspheres with a particle size of 1μm were stirred at 25°C for 10 minutes until homogeneous, resulting in a polystyrene microsphere dispersion. This dispersion was added to the flask in four portions, one-quarter of the total dispersion each time, and stirred for 10 minutes after each addition. After the entire dispersion was added, 10g of curing agent was added and stirred for 10 minutes. The mixture was then poured into a molding mold and cured in a 25°C, 50%RH constant temperature and humidity chamber for 48 hours to obtain the RTV cured material, which is the acoustic lens material.

[0081] Example 4

[0082] At 25°C, 100g of RTV615 was added to a 250mL flask. Using 20g of ethanol as a diluent, 40g of polystyrene microspheres with a particle size of 1μm were stirred at 25°C for 10 minutes until homogeneous, resulting in a polystyrene microsphere dispersion. This dispersion was added to the flask in four portions, one-quarter of the total dispersion, with stirring for 10 minutes each time. After the addition was complete, the mixture was dried in a 50°C oven for 2 hours to remove the ethanol solvent. Then, 10g of curing agent was added and stirred for 10 minutes. The mixture was then poured into a molding die and cured in a 25°C, 50%RH constant temperature and humidity chamber for 48 hours to obtain the RTV cured material, which is the acoustic lens material.

[0083] Example 5

[0084] At 25°C, 100g of RTV615 was added to a 250mL flask. Using 20g of ethanol as a diluent, 40g of polystyrene microspheres with a particle size of 10μm were stirred at 25°C for 10 minutes until homogeneous, resulting in a polystyrene microsphere dispersion. This dispersion was added to the flask in four portions, one-quarter of the dispersion each time, and stirred for 10 minutes after each addition. After the entire dispersion was added, the flask was dried in a 50°C oven for 2 hours to remove the ethanol solvent. Then, 10g of curing agent was added and stirred for 10 minutes. The mixture was then poured into a molding die and cured in a 25°C, 50%RH constant temperature and humidity chamber for 48 hours to obtain the RTV cured material, which is the acoustic lens material.

[0085] Example 6

[0086] At 25°C, 100g of RTV615 was added to a 250mL flask. Using 20g of dimethyl silicone oil as a diluent, 40g of polystyrene microspheres with a particle size of 1μm were stirred at 25°C for 10 minutes until homogeneous, resulting in a polystyrene microsphere dispersion. This dispersion was added to the flask in four portions, one-quarter of the total dispersion each time, and stirred for 10 minutes after each addition. After the entire dispersion was added, 10g of curing agent was added and stirred for 10 minutes. The mixture was then poured into a molding mold and cured in a 25°C, 50%RH constant temperature and humidity chamber for 48 hours to obtain the RTV cured material, which is the acoustic lens material.

[0087] Example 7

[0088] At 25°C, 100g of RTV615 was added to a 250mL flask. Using 30g of ethanol as a diluent, 60g of polystyrene microspheres with a particle size of 1μm were stirred at 25°C for 10 minutes until homogeneous, resulting in a polystyrene microsphere dispersion. This dispersion was added to the flask in four portions, one-quarter of the dispersion each time, and stirred for 10 minutes after each addition. After the entire dispersion was added, the flask was dried in a 50°C oven for 2 hours to remove the ethanol solvent. Then, 10g of curing agent was added and stirred for 10 minutes. The mixture was then poured into a molding die and cured in a 25°C, 50%RH constant temperature and humidity chamber for 48 hours to obtain the RTV cured material, which is the acoustic lens material.

[0089] It is understood that the acoustic lens material obtained in the above embodiments can be further processed to produce an acoustic lens.

[0090] Example 8

[0091] Example 8 is basically the same as Example 1, except that the polystyrene microspheres in Example 1 are replaced with polystyrene microspheres of the same mass and a particle size of 20 μm.

[0092] Example 9

[0093] Example 9 is basically the same as Example 1, except that the polystyrene microspheres in Example 1 are replaced with polystyrene microspheres of the same particle size and with a mass of 15g.

[0094] Comparative Example 1

[0095] At 25°C, 100g of RTV615 was added to a 250mL flask. 10g of curing agent was added, and the mixture was stirred at 25°C for 1 hour. After mixing evenly, the mixture was poured into a molding mold and placed in a constant temperature and humidity chamber at 25°C and 50%RH for 48 hours to cure, thus obtaining the RTV cured product, which is the acoustic lens material.

[0096] Comparative Example 2

[0097] Comparative Example 2 is basically the same as Example 1, except that the polystyrene microspheres in Comparative Example 2 are replaced with 1μm polystyrene microspheres and 10μm polystyrene microspheres with the same total mass and a mass ratio of 1:1.

[0098] Comparative Example 3

[0099] Comparative Example 3 is basically the same as Example 1, except that the polystyrene microspheres in Comparative Example 3 are replaced with 0.1 μm polystyrene microspheres of the same mass.

[0100] Comparative Example 4

[0101] Comparative Example 4 is basically the same as Example 1, except that the polystyrene microspheres in Comparative Example 4 are replaced with 70g polystyrene microspheres of the same particle size.

[0102] Comparative Example 5

[0103] Comparative Example 5 is basically the same as Example 1, except that the polystyrene microspheres in Comparative Example 5 are replaced with 10g polystyrene microspheres of the same particle size.

[0104] The following table shows some parameters of each embodiment and comparative example, as well as the surface Shore hardness, acoustic impedance, acoustic attenuation, and acoustic reflection coefficient data of the obtained RTV cured products:

[0105]

[0106]

[0107] The test standard or test method for surface Shore hardness is as follows: GB / T 531.1-2008;

[0108] The test standard or method for acoustic impedance is as follows: YY / T 1668-2019;

[0109] The test standard or test method for acoustic attenuation at 5MHz is as follows: YY / T 1668-2019;

[0110] The test standard or test method for sound reflection coefficient is as follows: the acoustic impedance of the material is obtained by testing, and then the sound reflection coefficient is calculated using the sound intensity transmission coefficient formula in the YY / T1668-2019 standard.

[0111] Comparative Example 1, without the addition of polyethylene microspheres for modification, yielded an RTV cured product with a surface Shore hardness of 15.9, an acoustic impedance of 1.07 MRayl, an acoustic attenuation of 15.4 dB / cm at 5 MHz, and an acoustic reflection coefficient of 5.52%. It is evident that the RTV cured product of Comparative Example 1 without polyethylene microsphere modification has a relatively low acoustic impedance of only 1.07 dB / cm and a relatively high acoustic reflection coefficient of 5.52%.

[0112] Generally, the acoustic impedance of the material used as a sound-transmitting material is preferably between 1.1 and 1.5 Mrayl, the sound attenuation at 5 MHz is below 28 dB / cm, and the sound reflection coefficient is below 2.0% to ensure ultrasonic imaging sensitivity and image quality. Typically, the surface Shore hardness of the material used as a sound-transmitting material is between 17 and 60; too low a hardness results in a short service life, while too high a hardness leads to poor skin-friendliness. Preferably, the surface Shore hardness of the material used as a sound-transmitting material is between 19 and 50, and more preferably between 25 and 45.

[0113] Comparative Example 2 is a mixture of two polyethylene microspheres with different particle sizes, meaning the particle size is not highly uniform. According to the results, the non-uniformity of the polystyrene microsphere particle size has a significant impact on the sound attenuation. Its sound attenuation reaches 29.4 dB / cm at a frequency of 5 MHz, indicating that its sound intensity loss is large, which will seriously reduce the sensitivity of the ultrasonic probe.

[0114] The particle size range of polystyrene microspheres in Comparative Example 3 was extended to 0.1 μm. Due to the small particle size, the silicone rubber was difficult to penetrate between the microspheres because of its viscosity. The RTV silicone rubber system was difficult to disperse. Although its acoustic impedance was also improved, the acoustic attenuation increased even more. Its acoustic attenuation reached 28.9 dB / cm at a frequency of 5 MHz, indicating that its acoustic intensity loss was large. This will seriously reduce the sensitivity of the ultrasonic probe.

[0115] In Comparative Example 4, increasing the amount of polyethylene microspheres to 70g reduced the modification effect on RTV silicone rubber. Its acoustic attenuation at 5MHz frequency increased significantly to 34.7dB / cm, indicating that its acoustic intensity loss was large, which would seriously reduce the sensitivity of the ultrasonic probe.

[0116] In Comparative Example 5, reducing the amount of polyethylene microspheres to 10g reduced the modification effect on RTV silicone rubber, but significantly increased its acoustic reflection coefficient to 2.51%, indicating that the acoustic transmittance was low, which will affect the quality of ultrasound imaging.

[0117] The modified RTV cured products prepared in each embodiment have an acoustic impedance of 1.12 Mrayl or higher, an acoustic attenuation of 28 dB / cm or lower at a frequency of 5 MHz, an acoustic reflection coefficient of 2.1% or lower, and a surface Shore hardness of 17 to 40.

[0118] Comparing Comparative Example 1 with Examples 1, 2, and 8, it is evident that the addition of polystyrene microspheres to RTV615 only slightly increases the acoustic attenuation coefficient, particularly in Examples 1 and 2 where the increase is minimal, while the surface Shore hardness and acoustic impedance are significantly improved. Examples 1, 2, and 8 show that when the particle size of the polystyrene microspheres increases within the range of 1 μm to 20 μm, for example, when the microsphere particle size increases to 20 μm, the diffraction effect of ultrasound in the corresponding modified silicone rubber becomes worse, resulting in a slight increase in the acoustic attenuation coefficient. Therefore, the preferred particle size of the polystyrene microspheres is 1 μm to 10 μm. Regarding hardness, the modification effect of 1 μm polystyrene microspheres is lower than that of 10 μm and 20 μm polystyrene microspheres, but the acoustic impedance, acoustic attenuation, and acoustic reflection coefficient are all superior to those of 10 μm and 20 μm polystyrene microspheres, making 1 μm polystyrene microspheres preferred.

[0119] As can be seen from the comparison between Example 1 and Example 3, using dimethyl silicone oil as a diluent to prepare polystyrene microsphere dispersion has a certain improvement on the hardness of the prepared silicone rubber. This is because dimethyl silicone oil can participate in the curing reaction of RTV as an active monomer, increase the crosslinking density, and thus increase the hardness of silicone rubber.

[0120] As shown in Examples 1, 4, 7, and 9, increasing the amount of polystyrene microspheres can further improve the acoustic impedance and Shore hardness of the modified RTV silicone rubber, but the acoustic attenuation also increases. Relatively speaking, in Example 7, with 60 parts of polystyrene added, the increase in acoustic attenuation of the modified RTV silicone rubber was relatively large, indicating that if the amount of polystyrene microspheres added continues to increase, i.e., if the amount of polystyrene microspheres is too large, it may seriously affect the acoustic properties of the silicone rubber.

[0121] As can be seen from Example 6, when dimethyl silicone oil is used as a diluent and the amount added is 20 parts, and the amount added is 40 parts, the acoustic impedance value of the modified silicone rubber of the present invention can be increased from 1.07 MRayl of pure RTV silicone rubber to 1.32 MRayl, which is closer to 1.5 MRayl of human tissue; the acoustic reflection coefficient is reduced to 0.41%, indicating that it has higher sound transmission; at the same time, the acoustic attenuation only increases from 15.4 dB / cm at 5MHz to 19.9 dB / cm, indicating that its acoustic attenuation characteristics are not significantly affected and remain at a low attenuation level; the hardness can reach 36.9, and the service life and skin-friendliness can be satisfied. Therefore, the modified silicone rubber of Example 6 is a highly practical acoustic lens material.

[0122] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0123] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims, and the specification can be used to interpret the content of the claims.

Claims

1. A modified silicone rubber, characterized in that, The invention includes an RTV silicone rubber cured matrix and polystyrene microspheres dispersed in the RTV silicone rubber cured matrix, wherein the polystyrene microspheres are monodisperse particles with a particle size of 1 μm to 20 μm; In the modified silicone rubber, the RTV silicone rubber cured matrix is ​​110-140 parts by mass, and the polystyrene microspheres are 15-60 parts.

2. The modified silicone rubber as described in claim 1, characterized in that, The polystyrene microspheres have a particle size of 1 μm to 10 μm; And / or, the particle size Cv value of the polystyrene microspheres is <3%.

3. The modified silicone rubber according to any one of claims 1 to 2, characterized in that, In the modified silicone rubber, the RTV silicone rubber cured matrix is ​​110-140 parts by mass, and the polystyrene microspheres are 15-40 parts by mass.

4. A method for preparing modified silicone rubber, characterized in that, Includes the following steps: RTV silicone rubber, polystyrene microspheres and diluent are mixed evenly, and then a curing agent is added for curing, so that the polystyrene microspheres are dispersed in the RTV silicone rubber cured matrix formed by the curing of RTV silicone rubber; In the modified silicone rubber, the RTV silicone rubber cured matrix is ​​110-140 parts by mass, and the polystyrene microspheres are 15-60 parts; the polystyrene microspheres are monodisperse particles with a particle size of 1μm-20μm.

5. The preparation method according to claim 4, characterized in that, By weight, the RTV silicone rubber comprises 100 parts, the polystyrene microspheres comprise 15-60 parts, the diluent comprises 10-30 parts, and the curing agent comprises 10 parts.

6. The preparation method according to claim 4 or 5, characterized in that, The diluent is selected from at least one of reactive diluents and non-reactive diluents; When the diluent contains a reactive diluent, the reactive diluent participates in the curing process; When the diluent contains a non-reactive diluent, before adding the curing agent for curing, the following step is also included: removing the non-reactive diluent from the uniformly mixed material.

7. The application of the modified silicone rubber as described in any one of claims 1 to 3 as a sound-permeable material.

8. A sound-transmitting element, characterized in that, Its components include the modified silicone rubber as described in any one of claims 1 to 3.

9. An ultrasonic probe, characterized in that, It includes a probe body and an acoustic transmission element as described in claim 8 disposed on the surface of the probe body.

10. An ultrasound diagnostic device, characterized in that, It includes the main unit of the device and the ultrasonic probe as described in claim 9.

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